There must be many times when De Gea arrives at training or for a match and he gets a sort of 'Goundhog day' feeling... I've been here before, done that, bought the 't' shirt etc. David is one of the very few still remaining who were here with SAF, maybe some of this 'rinse and repeat' especially with managers, etc. is getting to him at times. Allowing himself to be beaten on the near post, even accounting for Maguire's 'nutmegging' is the kind of mistake he never made.
We are looking good, there is no doubt about it with the impact of Fernandez, Pogba back and performing well, Matic reinvigorated, Mason Greenwood emerging as possibly our best young prospect since Ryan Giggs. However even under Ole if the old spirit returns and performances continue to improve, it is not something new for David De Gea, he's seen and done it all before.
De Gea is a great keeper and has been a good servant to this club, but maybe in his own interests its time to move on to find pastures new.
If it is the above i.e. 'groundhog-day' type issue that is the problem, it can only be solved by him moving, if its something else then there needs to be a full appraisal done and quickly