You had White's queen dead twice in three moves, and both times you took something instead of catching her; the clock you burned getting those two moves wrong is the clock that ran out on move 36.
The flag is the thing that stings, so it is worth saying where it was actually purchased. Not at move 36, and not in the endgame, which you played well. At moves 13 and 14, where three and a half minutes of thinking produced two moves that gave away a won game.
13...Nxf2 -- the pawn instead of the queen
White's 13.Qg4 was the blunder that should have ended it, dropping the position from +0.4 to -3.2. Material was dead level at that moment. The whole of that -3.2 was White's queen having nowhere safe to live.
The move was h5. It hits her before she is organised, and after h5 Qf4 Qg7 Nc3 e5 Qe3 Black is still around -3.1 with the queen shuffling and every Black piece pointed at White's position. Instead 13...Nxf2 took the pawn and gave the whole thing back, because the pawn was defended: Rxf2 Nb3 Bb5+ Kf8 Kh1 Qxf2 wins the exchange back for you and lands at +0.0. Fifty-seven seconds to find a move that traded a winning attack for a level ending.
The idea to carry: when the enemy queen is the reason you are winning, the move that improves your position is the one that takes another square away from her, not the one that wins a pawn somewhere else.
14...Ne2+ -- the check that cost you the piece the plan needed
White missed it too, 14.Qg3 taking the position from +0.0 to -5.7, and this is the one that decided the game.
The engine's move was Ne4, the f2-knight stepping out to hit the queen on g3. She has one reasonable square, and after Ne4 Qe3 Nf5 Bb5+ Kf8 Qxc5+ she is gone: Nf5 attacks her from d4, and the moment that knight leaves d4 your Bc5 is attacking e3 as well, so she is hit twice with nowhere to go. Bb5+ Kf8 buys a tempo and nothing else, and Qxc5+ is White paying the queen for a bishop because that beats losing her for free. Black is up a queen for a bishop, -5.6.
You played 14...Ne2+ first. Twenty-nine seconds, and the position went from -5.7 to +0.9. The check is real, but 15.Bxe2 removes the d4-knight, and the d4-knight is the piece that plays Nf5. You spent the executioner on a check. What was left was 15...Ne4+ 16.Kh2 Qxf1 17.Bxf1 Nxg3 18.Kxg3, which looks like a haul and is not: count it and material comes out exactly dead level, with White's pieces better placed than yours.
The idea to carry: a check inserted before the main idea is not free. Name the piece that gives it, then re-run the line you actually want with that piece gone.
20...d4 -- three seconds, and the first move on fumes
By move twenty you had three seconds. This is the first move where the clock is visibly making the decision, and it went from +1.4 to +3.0.
The move was f5, which takes e4 away from White's pieces and buys the time to play a6: f5 Be3 Rc8 Nc3 a6 Bd3 keeps it at +1.4 and, more to the point, keeps b5 covered. Pushing 20...d4 ran the pawn past its own support and left b5 wide open, and 21.Bb5+ arrived immediately, chasing your king to e7 where it sat in the way of your own rooks.
The idea to carry: when you are worse and short of time, the cheapest move is the one that stops a check, because a check is the one thing you cannot ignore on five seconds.
34...e4 -- the fightback that deserved a result
White's 34.Nh4 handed it back, +0.0 to -2.4, and you found 34...e4 in thirteen seconds. It was the engine's first choice, and after Re2 Rec7 Rf2 Ke6 g4 Rxc2 Black is simply winning. Then 35...Rxc2 went in, 36.Bxb5 came back, and the flag fell.
This is the part of the game to actually take seriously. You were at +3.6 down on move thirty, on nothing but increment, and you ground it to a position where you were better by more than two pawns. Sixteen moves at five seconds each against a player rated within twelve points of you, and you came out ahead on the board.
Phase notes
Opening. Nothing to fix. 9.a3 was a free tempo in a position that could not spare one, and 9...Nxd4 was the engine's first choice, with Qd1 Bd6 Re1 Nc6 c4 dxc4 to follow. You were better out of the opening on merit.
Middlegame clock. Three moves cost you the game twice over: 11...Ne4 at 2m04, 13...Nxf2 at 57 seconds, 14...Ne2+ at 29 seconds. All three lost ground on the eval. That is three and a half minutes spent to make the position worse, and it is the same three and a half minutes you needed at move 36.
Endgame. 30.Nf3 dropped White from +3.6 to +0.7 and 30...e5 was the only move that held, found on the increment, with Bc4 Rc5 Bb3 b5 Rf1 a5 to follow. Your defensive play under a hostile clock is a real strength and this game is the cleanest evidence of it so far.
Profile check
Is this the same mistake as last time? The habit is the same, the surface is inverted, and that is worth knowing.
The saved item says you accept the first plausible move in a winning position without checking forcing replies, as with the natural rook move in the Russia-Melanesia game where 48 seconds did not turn up the forcing continuation. Here you did the opposite: you found forcing moves and played them without checking the alternative. Both are the same underlying gap, which is that once one candidate looks good you stop generating candidates. Confirmed, and widened: the rule is not "prefer forcing" or "prefer quiet", it is that a winning position needs at least two candidates compared before you commit.
New item, and it is specific enough to be worth its own line: inserted checks. 14...Ne2+ cost you the exact piece the winning idea required. Before a zwischenzug, re-run the main line without the piece that delivers it.
Contradicted, and I want this one on the record: the saved note about treating bad positions as finished. In the berkut47 game you gave up on move 42 in a lost but playable position. In this game you were down +3.6 with three seconds and no realistic hope, and you outplayed the position back to winning. Whatever that habit was, it did not show up here.
What to drill next
- The position before 14...Ne2+ (drill it). Beat the engine from here three times running. This is the single most expensive move you have played this week and the improvement is one quiet knight move.
- Trapped-piece puzzles. Both errors in this game were failures to hunt a queen that had nowhere to go, and this theme is exactly the pattern of taking squares away instead of taking material.
- Converting a winning position. The recurring one. You reach won positions reliably and lose them in the two or three moves after you notice they are won.
Before you insert a check, name the piece that gives it, then re-run the line you actually want with that piece gone.