Avast free slows the speed to 20 Mbps. downloading (Optical fiber)

Hello
I have optical fiber and Avast Free slowed down speed to 20 Mbps.
If Avast disabled the bitrate goes to 200Mbps
Firefox browser and test pattern: https://www.sfr.fr/mire-test-debit
So the problem is Avast antivirus ?
Regards
jmp93

Does avast really affect your speed, or is it just messing with the speed test ?

To find out, download a biiiiiig file and take the time, then turn off shields and repeat

is there a minor or big time difference ?

just did test I geting 480mbit out of 400mbit I pay for, maybe some rogue setting you made?