Server Version#: 1.23.3.4692
Player Version#: web 4.58.1
There seems to be a bug with the (is) syntax when saving a filter. After saving, it reverts to [contains: =value] which prevents the search value from matching as it had previously done.
Pre save: https://i.imgur.com/t6SJQu6.png
Post save: https://i.imgur.com/w6D0s3a.png