idk what u changed in the current patch, but I started having same issue as well,
i tried on other servers to see if the problem occur and it does not , its just something related to fgunz source,
on other games it works perfectly fine,
I even tried formatting my pc and installing a fresh version of win 10 with newest driver updates still same issue.
I tried all the solutions your provided in this post and yet again no changes.
Please have a deeper look towards this issue that many players are having atm.
Thank you.