@1c699b409a68f19fba95 do you have a large number of category options, categories, category option combination?
If so then this could be the reason behind this issue, and others have found @Matthew_Boddie 's post as a solution in a topic with the similar question:
Please confirm if it’s the same issue and if that suggestion solves your issue. If not please provide more details such as network log of the related requests in the browser’s DevTools F12 and the Catalina.out log (without authentication/sensitive info).