Overextrusion on first layer

Welcome!

Yes there is. It’s called Bottom Surface Flow Ratio. Near the bottom on Quality tab. You must turn on Advanced switch (just under Filament Choice).

You might also consider doing some calibration of your filament. The settings Bambu Lab used are usually pretty good but also conservative. Many filaments work perfectly, others need some adjusting.

I just wrote a a thread you might find interesting (he says, shamelessly self promoting :grin:).

There are some Calibrations in Bambu Studio but there are Flow Rate and Temp towers in OrcaSlicer which is a fork (variation) of BL Studio. That’s what it sounds like you need. It’s free and coexists with BL Studio.

Here’s some info on it: