Validateaddress RPC call returns invalid for a valid address

Hello, I have some python scripts that make litecoin rpc calls. One such call is to the validateaddress rpc function. I am calling validateaddress with a multisig (M prefix) address and getting an “invalid” response ({‘isvalid’: False}). If I use the legacy format (3 prefix) it still returns invalid. If I skip this call, other rpc calls also complain about the address being invalid (for example listunspent rpc call). The address shows fine on a block explorer so I’m sure it’s a valid address.

I know that this was working in version 0.18.1, but I’m now using version 0.21.2.

Has anything changed for validateaddress between these versions that would cause this to fail?

Keep using the version which worked. Don’t just update for an update’s sake.