Problem with sorting orders in a SharePoint list

I have created a list in SharePoint and I want the products ordered in it to be sorted by year and month. I created a new column for month and year and then set the grouping according to the Year and Month lists I created. Everything was working fine for a long time, but about a month ago it stopped working and I get the message "nothing found to show here "try removing filters to get results". Unfortunately, I don't have any filters set, when I clear my browser data, the products appear on the list for a few minutes and the message returns again. I checked different browsers and it's the same on each, in the MS Teams application there is the same situation and after logging out and logging in again, the products appear and then disappear again. Only through the Teams application on the phone everything works fine. The problem is not only with me but with all members of the list. I would like to ask for help because everything was working fine for a few months and suddenly stopped.