Task manager is unable to show the number of tabs. It shows tasks and processes.

That's a lot of processes for only two tabs. We need to investigate.

First, could you compare the Windows Task Manager's "Details" tab with Firefox's built-in Task Manager (either Shift+Esc or about:processes). Do they both show 35 processes? Firefox's should show the specific sites assigned to those processes, plus several for global purposes, such as add-ons, GPU, etc. The Process IDs should match between the two.

If Firefox shows that it has processes for sites you do not actually see open, please check Firefox View -- either click the "file drawer" tab at the left end of the address bar or type/paste about:firefoxview in the address bar and press Enter to load it. On the Open Tabs panel, are there any windows you don't see on screen?