qt.qpa.plugin: Could not find the Qt platform plugin "xcb" in ""

[coldspark29]

I have just updated the Qt version of my Raspberry Pi cross-compilation environment fro m 5.15.0 to 5.15.2, but now I am getting this infamous error again including these errors

qt.qpa.plugin: Could not find the Qt platform plugin "xcb" in ""
Failed to move cursor on screen HDMI1: -13
Failed to move cursor on screen HDMI1: -13
Could not set cursor on screen HDMI1: -13
Could not set DRM mode for screen HDMI1 (Permission denied)
Could not queue DRM page flip on screen HDMI1 (Permission denied)

I had the same issue using the previous version and I could solve it by adding

DISPLAY=:0
XDG_SESSION_TYPE=x11 

to my environment variables for SSH, but now I can't even run the program from the Pi itself.

I think I have all xcb libraries installed. I mean it worked before. Weird that it doesn't work with the newer Qt version.

Any ideas?