Also just a startup log.
15:58:13.096: ==== Startup complete ===============================================
15:58:13.098: Service '' not found
15:58:13.110: All scene data cleared
15:58:13.110: ------------------------------------------------
15:58:13.151: WASAPI: Device 'Realtek HD Audio 2nd output (Realtek High Definition Audio)' initialized
15:58:13.186: adding 46 milliseconds of audio buffering, total audio buffering is now 46 milliseconds (source: Urządzenie audio)
15:58:13.186:
15:58:13.324: adding 46 milliseconds of audio buffering, total audio buffering is now 92 milliseconds (source: Mikrofon/Wejście liniowe)
15:58:13.324:
15:58:13.367: WASAPI: Device 'Mikrofon (Realtek High Definition Audio)' initialized
15:58:13.370: adding 23 milliseconds of audio buffering, total audio buffering is now 116 milliseconds (source: Mikrofon/Wejście liniowe)
15:58:13.370:
15:58:13.726: Switched to scene 'Scena'
15:58:13.728: ------------------------------------------------
15:58:13.728: Loaded scenes:
15:58:13.728: - scene 'Scena':
15:58:13.728: - source: 'Przechwytywanie ekranu' (monitor_capture)
15:58:13.728: - scene 'Scena 2':
15:58:13.728: - source: 'fortnite' (game_capture)
15:58:13.728: - scene 'Scena 3':
15:58:13.728: - source: 'Minecraft' (game_capture)
15:58:13.728: ------------------------------------------------
From the Help menu, choose "Show Log Files". It will open a folder with your recent logs.
Sort the list by date. Open each one, latest first. Look through them for a line entry that indicates that recording or streaming is starting, and then another one that indicates it is stopping.
After OBS stops a stream or recording session, it then writes into the log information about performance that is used to troubleshoot. It mentions "lagged" or "dropped" frames in rendering, encoding, or uploading.
Without that information it's not easy to guess what is causing your issue. If you don't run OBS, start an output session, observe your problem, and then stop the output session (recording OR streaming) then this information is not in the log. If you do that, and information is still not in the log, then it is the wrong log file-- go to the next one.