Big Issue ue4.26 - Cant select things

Hi, i have big problem with ue4. After loading my project, its a matter of short time until i irregularly cant select assets or if i can, i sometimes cant move em or just the red arrow responses or just the blue or just blue and red together for example and if i did one time, i cant do it again because suddenly the same none arrow responses this includes foliage painted things also.

When i hover over an asset which is just unselectable for a period of time, the cursor turns into the standard desktop arrow icon.

It doesnt matter what asset or foliage sometimes this one works and this not and that in every combination.

I rly need help.