Audacity 3.3.1 showing miliseconds bug

I’ve merged more sounds into one audio file (mp3) for my new JS website/game. Then i’ve typed in my program when a sound starts and ends, in ms, trusting that Audacity shows correctly seconds:miliseconds, but it’s not. The sounds weren’t played correctly.
After struggling for few hours to find the error, thinking it was my bad, somewehere in my JS program, I’ve noticed that Audacity adds about 25ms at the beginning of that file when it’s opened!
I’ve opened my audio file in another audio editor (audiomass), and the timings are correct!
Thank you in advance, if you resolve this bug.

Moderator note: I removed the website links.

Greetings.

Boguslaw

MP3 adds some silence to the beginning and end.

MP3 is lossy (imperfect) and this is one of the side effects.

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