Sharpen foreground of VIDEO

I just shot a interview on video where the foreground that is the interviewee is out of focus and I tried to use video enhance AI to improve the sharpness but have not been able to see any improvement. I am wondering whether the fact that the background is in focus interferes and is stopping the program from sharpening the vision. Would a solution be to mask the background and which program would be the best to use to sharpen the video?

Davinci Resolve has features to correct focus which may be worth a look.

The free version is extremely powerful but has quite a steep learning curve for beginners;

My best suggestion would be to either downscale the video and run it through VEAI that way, run every frame into Gigapixel then shrink it to the original resolution until it loses the blur, or run every frame through Sharpen AI.