SUMMARY
Imagine I have a tag list 'A, B, C, D' ,and I have a brush get 'A, B' tagged.
When un-tag A and re-tag A on the brush, A won't show up until "adding tag C or remove tag B"
If un-tag 'A, B' and re-tag 'A, B' , A and B both not show up until add tag C

will affact the other brush in the same bundle but seems not always the same story
restart Krita will solve the issue.

STEPS TO REPRODUCE
1) Setting-> Manage Resource-> Krita_4_Default bundle-> choose b)_Basic-6_Detail for example
2) Remove tags 'Paint, Sketch'
3) Add tag 'Paint', nothing happened
4) Add tag 'Sketch', nothing happened
5) Add tag 'RGBA', now it show up 'Paint, Sketch, RGBA'

OBSERVED RESULT
Not add the tag until a "new" tag is added

EXPECTED RESULT
Add tag when it assigned

SOFTWARE/OS VERSIONS
Windows: Windows 10 20H2

ADDITIONAL INFORMATION