dark pact of trarthus bug

When the skill have a high trigger rate , the ruin stack will bug.
Self cast normally will not see the 7 stack , the stack should fade when reaching 7 stack.
When i use coc with the skill(no quality) , you can see the ruin reach 7 stack when i spamming the trigger skill ( spraying steel).
Moreover , when i use coc with skill(20 quality) , it even have chance to reach 8 stack during the process.

Notice that the 7 stack of ruin can really fail in ultimatum.(normally it will reset when reaching the 7th cast time)
Don't really know if it have affected other things or it is just visual client bug.

Video of testing:https://youtu.be/pWQsIyDNqB8