Filtering any company with an & sign in it does not work in MINT.
Simply put - there is a bug in MINT Filter by Company.
I tried to tell PAT at your support person but she didn't get it and I felt this was a waste of time.
If you filter by company with the & in the name.
It does not work. So, your filter has an issue with the & sign (and maybe some other encapsulated characters)
Go to Transactions and find any company with & in it. On the right, click on the option "Show All 1&1 Internet" and when you do - zero (0) transactions come up. Same with AT&T Wireless.
I'm 100% sure the issue is with the & being in the name.