Just want to determine you're talking about the right mixing service, because you mention that after logging in one day, your wallet has changed... but if you mixed coins with ChipMixer, you actually deposit and then receive "chips" with their own private keys. Or perhaps your tx did go through and you are just seeing a new session address.
Either way, better send your request to support with your original session ID/address: [email protected]
all works fine but after login one day later to check if the transaction is still stuck i see there was a different wallet.
Ah then it's good. Yes, you get a new deposit address after your session expires in 48 hours. You should have extended the session if your tx wasn't confirmed. But anyway, it should all be fine. Just email support with your different session deposit addresses... seems you've already done the RBF spend, so they'll need to know that.