We are using Lookup editor app and before we were able to scroll through all the 4000+ rows within a specific CSV file. Now it does not go over 100 rows.
We tried different browsers and also incognito and still the same behavior. This happen to all users.
It was noticed that there is a up arrow at the top and down arrow at the bottom so you can click/hold to quickly scroll through the rows. The bar is there but looks grayed out, so to get the rows to go down, we have to choose a row and then hold the keyboard down arrow to scroll through 4000 rows.