Sync Error after Opening App on my Phone after Severeal Weeks

Hello,

yesterday I opened my RemNote App after several weeks of not using it. Everthing worked fine. But I opened my desktop app (Chromium, PWA), quite old stuff I already deleted appears again. But that’s not the problem, because I could easily delete it. But the “Quick Add” Power-Up-REM exists now twice

grafik

It is not possible to delete it. AFAIK

Who can help me?
Kind regards
A_F