XF 1.5 pagination not working


Help please, pagination stopped working for me (switching pages - 1 - 2 - 3 ...... 7)

pagination in one section works, in the other it stopped working. How can this be? I did not enter the code for several years, the forum worked for a couple of years without creating additional topics. I started to notice that the page takes a long time to load and I saw that all the topics are on one page, although everything works correctly in the next section. The template is standard (default), did not change.

Plugins and add-ons for several years did not install and did not change anything. help me please