Similar issue that started today (noticed it now but cannot say for sure if it was working earlier today or not. I also receive the following error message when filtering now: "Api[name=crm-search, httpMethod=POST, subPath=/crm-search/search/ids] Failed to process your request. Error code was '400'. Error message was: {"status":"400","message":"Unable to execute query..."
I am experiencing a similar issue and have to scroll down to the individual contact to bring up the contact's data. Luckily I have less than 300 contacts, but it's a pain.