I have serious lags and bugs in Premiere Pro 26.3

Since I got Premiere Pro v26.3, I started having problems after some minutes of editing, everytime I use the menu above, either to export, render or save. It stays blocked, says, “not responding” and sometimes starts a minute later. But, if I try to do the same while using shortcuts, seems to be ok. 

Besides that, when working with heavy timelines, with several effects, it starts to work slow and make some bugs. 

I didn´t have this issue with previous versions. My computer is very powerful, so I don´t get the problem. I even reinstalled Premiere, but didn´t solve the issue.

Could you please tell me what to do? Thanks!