Audio gets more silent suddenly.

All my recordings go without a problem, but the moment i tried to sing single notes for longer than 3-4 seconds the volume of that note goes way more quiet that the beginning and if there is a short stops of a millisecond or so it continues on with normal volume, Ireally got noIdea what i can do to solve this so please help.

All my recordings go without a problem

All your voice recordings.

the moment i tried to sing single notes for longer than 3-4 seconds the volume of that note goes way more quiet

That means you’re singing into a system with automatic noise reduction. The system knows noise by duration. Any sound present for longer than a set number of seconds must be noise and get rid of it. Normally, this is OK because noises such as air conditioning or computer fan noise are constant.

Auto noise reduction and other automatic processes hate music.

You can do into Windows setups and turn those corrections off. Fair warning, your quiet background noise performances will go with it.

https://manual.audacityteam.org/man/faq_recording_troubleshooting.html#enhancements

Koz