Problem with Linux Capabilities for kopia and kopia-ui

When I set CAP_DAC_READ_SEARCh for kopia-ui (on Ubuntu Noble) with

$ sudo setcap cap_dac_read_search=+ep /opt/KopiaUI/kopia-ui 
$ kopia-ui 
kopia-ui: error while loading shared libraries: libffmpeg.so: cannot open shared object file: No such file or directory

it seems not to be able to open libffmpeg.so afterwards. I do not fully grasp why…