1. create 21 sites
2. assign 20 site roles to the user (everything is fine till this point)
3. assign the 21st site role to the user
4. press save
5. "Your request completed successfully" appears However if you list the site roles of the user it doesn't get listed.
Looking at the database the UserGroupRole table doesn't contain the 21st site role triplet.
If I set the page size to a bigger value (75) then the save is successfull and we have 21 site roles both displayed and in the database.
If we go back to page size 20 and press save again then the 21st site role is removed.
I guess Liferay doesn't take the pagination into account while saving.