I ran the diagnostic to check allocations , this is what i got, not same as yours, main allocation comes as expected in the beginning but from the 6th second (from the period I highlighted) till end there is a small allocation coming from other sources. Maybe I should uninstall monogame 3.7.1 and install it again?, I installed it just 2 weeks ago, and it was a brand new install. The small allocations start after around 2.32 seconds (after the big allocation in the beginning)
as mentioned before I don’t have any code in the sample empty project.
I tried a few more things and I started to get allocations for mouse and windows, it looks like it is something that windows is doing and doesn’t looks like is Monogame doing it, including the snap I put in this message