For Football Manager 2020 Editor - from what I can see it's because the hours played are being overridden. If you click the edit icon on the game when hovering over it, then select "Use tracked time" does that fix it?
Yes, that did indeed help. I don't know why it was like that. Maybe I accidentally overwrote it.
Almost everything seems to be back, except the Steam Tools are still missing. That would be the Football Manager Editor 2015, 2016, 2017, 2018 and 2019. In the Tools section at Steam I can see the last usage and the number of hours. Only the last current editor is available here.
Sorry for the circumstances. I think I will never delete games again.