When i select values for legendary potential and weavers will, higher than 2 and 7 respectively, they revert to 2 and 7.
A very short video displaying the problem:
https://imgur.com/a/9GvJKjr
I have logged in to check it, and can confirm that it does reset the values to 2 and 7 respectively for LP and WW. However… It seems to be doing it only after re-opening the rule window.
On your recording I can see that you have setup custom name for the rule, if you were to remove that custom name and use the auto-generated one, it looks like filter is saving the rule correctly (“Show all Lvl <= 51 with at least 3 Legendary Potential or 12 Weaver’s Will items”), but it does indeed resets the values back to 2 and 7 after I reopen the rule window.