Trying to withdraw small amount of bitcoin, have the google authenticator setup.
Have tried 4 different receiving addresses. all error with: "Bitcoin withdrawal address entered is invalid"
Have also verified address is valid at https://www.blockchain.com/btc/address/

Please help.

Can you give some examples of what you entered as withdraw address?

Bech32 addresses are not supported (yet), still need more testing on this side.

Please use a P2SH address which starts with 3 for now, it should be burning segwit fee as well.