According to patch notes:
https://www.arcgames.com/en/games/playstation/neverwinter/news/detail/11352603-patch-notes:-version:-nw.120.20200106a.10Fighter: Any
The class mechanics "Dig In" and "Seethe" now cancel any at-will attacks currently in use rather than queuing up behind the current at-will.
But in fact only Seethe cancels at-will, dig in is not
Steps to reporduce
1 - log in on 80 lvl vanguard fighter
2 - do any shield-related at-will
3 - in the middle of at-will animation press r1 (dig in)
ER:
"Dig in" will cancel at-will animation ant put shield immidiately
AR:
"Dig in" starts only after at-will animation completed