No.
As said by Huey, it changes if you delete or rename your data directory, but if you don’t touch your data directory your onion address will remain unchanged.
Of course, a malicious user can change his onion address.
That’s why it’s recommended to trade carefully, eg trade with peers you know from successful past trades
being honest.
Bisq is developing some reputation/signature features but that will need some time.
Some other advices → Same onion address, different people - #22 by Homard
One great way to trade safe is to trade crypto/BTC. There you are in a safe environment 