Sleep help: mid night screaming

One of my twin boys (23 mos) has recently started waking every night in the middle of the night. he screams and screams until we take some sort of action. he can scream for a LONG time, like 45 min to an hour. no breaks. no sitting down.

I realize what we’ve been doing is reinforcing this behavior but I’m not really sure what else to do. my husband has been getting up with him and taking him to our guest room or basement to sleep. if one of us goes in and does a short reassurance check, he just screams louder which wakes his twin brother up.

he was previously a solid sleeper who did not wake at all in the middle of the night. we haven’t changed anything about our routines.

any ideas?