Steps to reproduce:

1. Create a group called "comma,group"
2. Exclude that group from sharing

Expected result

Group properly excluded

Actual result

(not tested but guessing) group name is split into two groups "comma" and "group", so exclusion cannot work.

Note that other places like the "enable app for groups" use JSON to store the groups array.

The "exclude sharing for groups" feature need to be fixed to also use JSON.

CC @schiesbn