Even with concurrency = 1 set in the configuration, the bot still accepts multiple challenges at the same time. This seems to be a concurrency-limit bug in lichess-bot-bridge.

When several bots challenge almost simultaneously, the bot accepts 2–3 challenges concurrently. In the screenshot example, it accepted games from SybBot, FataliiBot, and turkjs while it was already playing one game. Since my hardware cannot run multiple engine instances, two of those games were lost on time.

This issue happens frequently:

The bot starts a single game.

Multiple new challenges arrive close together.

concurrency = 1 is ignored and all challenges are accepted.

Engine overloads and crashes.

Bot cannot reconnect to the earlier games and loses them on time.

Configuration:
concurrency = 1

Expected behavior:
When running with concurrency = 1, every incoming challenge beyond the first should be ignored or declined until the current game finishes.

Actual behavior:
If challenges arrive within a tight time window, the bot accepts all of them, bypassing the concurrency limit.

This is causing repeated timeouts and rating loss. A strict enforcement of the concurrency limit is urgently needed, especially for users running on limited hardware.