As patch notes from 10/8/2019 say:
"The sigil progress tooltip now correctly indicates Trove mastery instead of Total mastery."


No, that wasn't the point of the bug, problem is in the numbers. You don't get new mastery sigil with Trove mastery levels since geode first came out (about 1,5 years ago), you get them as milestone every 50 or so Total Mastery Levels.

Solution: Change it so it correctly says number of total mastery level and revert it to reffering to total mastery in text, as sigil changes with that, and not with trove mastery. So in the picture above it should say: "731/750 Total Mastery Rank to next tier"