I had the same, different route though.
Vendor: Samsung
Device name: Galaxy S10
Device codename: beyond1lte
Previous version: e-2.5-t-20241109446827-community-beyond1lte.zip
Upgraded to: e-2.6.4-t-20250103459146-community-beyond1lte.zip
Ran into this issue empty launcher screen. Tried to go to U (e-2.6.3-u-20241217455570-community-beyond1lte.zip) failed on recovery, manually updated recovery, got T. Unfortunately date corrupt so had to wipe all. Started setting up phone, apps and stuff al fine, reboot issue is there blank screen with bliss launcher after unlock. Wiped all data started again, reboot again issue. Until I figured maybe it is my preference for a small font and icons size.With an empty screen you can get to settings and change those, reset to defaults and icons back. Set it too small everything fine, reboot empty screen. On my S10 this issues happens if you choose the smallest two icons sizes, if you go with bigger it’s fine. This issues with bliss is present in both the U and T version of 2.6 for my device. Worked well with 2.5 and vaguely remember there was even a 6x5 icon grid, which is gone.
Opened git issue (Bliss launcher has empty icon screen (#8459) · Issues · e / Backlog · GitLab)