WI-FI constantly turning itself off

Okay so I got this phone second hand, it is the Galaxy S21 FE 5g, the wifi constantly turns itself off after about 10-15 minutes on the new ui 6 update, i’ve been through all settings involving samsungs smart connect, and factory reset multiple times. no cracks or outside damage. the bluetooth is fine so I know it’s wifi specific and happens on every network. it’s not my main phone but I would like to invest a little into fixing it, I just don’t know what i’d need to replace or if samsung is still as repairable as it used to be, i’ve had an iphone as my main for quite a while now