I have a number of sites where I have transferred coins in the past, just to mention some examples:
ONE - Tranquil.finance - Harmony
STG - Stargate official site - SmartChain
FTM - Fantom wallet- Fantom
…
When I go “trying” to withdraw the coins from such sites I get as expected the request for transaction confirmation in MM however the target withdrawal address shown IS NOT my wallet address.
I did this a number of times in the past and the withdrawal has always been MM since this was also the only source where the coins were original transferred from.
Make sure you connect the correct account from your MetaMask wallet to the respective dapps to trigger the withdraw. I don’t know how they work or what are you doing exactly, so it would be best if you contact Support team at https://support.metamask.io and click Start a Conversation
Once you click Start a conversation a live chat bot will appear on your screen. It will give you an automated response at first, but afterwards you should be able to contact the support team directly.
I don’t see how this could be wrong. I have a single account always used via FF so there’s no possibility to have the wrong account as far as I can tell.
Also the address reported within the wallet is correct.