Just flicked through your career, you appear to be doing all your work under your FTP from May until the past 2 weeks, where you then did some work over FTP but then dialled it back with Mills and Fang Mountain, and then again this week with Mills and Avalanche Spire.
Are you modifying the plans to avoid the over Threshold work? I think that is the main issue here. You need to be working over your current threshold to grow it, dialing it back under threshold will lead to what you are seeing.
I’d suggest dropping down to Mid Vol, making sure you hit ALL the sessions and all the intervals, use the extra rest days to make sure you hit the prescribed workouts.
Even Base should have had workouts over Threshold, ie Mid Vol Base
and build has a load of them, ie Mid Volume
