programms with file export options often show one dialog box for the location and name select, then a second for special options and final export, for example in Gimp you hoose export to jpg and the location box comes normally and fast, then you confirm to export and a second dialog should show up to set some special file option and when you hit the export button it finally is being exported - this second box is the problem

the second export file box sometimes shows up fast, but normally it takes some time like several seconds up to longer times like 30 seconds

it is easily reproducible by just going to the process several times, even with the same file, there is no rule for when it happens or when not, it happens with a clean desktop, CPUs unoccupied and 3000 or more megas of free memory 

a dependency problem appears, when the dialog had a delay the final file save/export progress bar takes time too and often stays some time at the end until finally closing the first file select dialog that is where the progress bar runs

I have checked it on Ubuntu, Linux Mint Ubuntu, and Kde Neon Ubuntu all with plasma 5.21.5, but is happening for long time now

I am running a 12.6 kernel with realtime scheduler compiled, but it happens also on the standard ticker kernels, my HD has enough free space Sata3 

I am not sure If I have chosen the right component this issue depends on, but I think you will change it if not
thanks