I'm having the same issues, every time I save an estimate or invoice or any other transactions.  It keeps reverting back to a previous customer or supplier and I have to search for the customer or supplier I was working on.  It does save the transaction, but very frustrating to have to keep searching for the one you are working on.

I've tried the suggested incognito window and it still does it.

Hoping this can be fixed, as it is really annoying!