Except if parameters has been changed since last time we discussed about that, @novames00 only allocate to Krita 2GB ram of the 10GB ram available on computer…
Copying a large amount of data in memory could take time if OS or Krita start to swap on disk.
But I’m not sure data in clipboard manager use Krita’s memory as clipboard manager is an independent software on system…
The best thing might be to open a bugs, with some detailled explanation about current configuration, and condition in which the problem happens…
Grum999