I experience severe frame drops on constant intervals whenever my gpu ( intel i51240p iris xe) hits 90-100% usage while AC plugged in and no frame drops when playing in battery since gpu only hits 40-50% usage. I experience this issue in almost every game like valorant, witcher 3 and etc.
intel i5 1240p (12th gen)
2x 4gb ram (3200Mhz)
512 Gb ssd
Try changing power settings on Windows and BIOS (if you have such options) and fan/cooler settings... Also, are you using the graphics driver from your laptop's website? if not, you should try it...