I-Firefox Isithangami Sokwesekwa

Summary of my current relevant software/hardware:

FireFox (UK): 113.0.2 (64-bit)
Windows 10 Pro(UK): 
 Vers.: 22H2
 Installed on: 2021-01-23
 OS build: 19045-2965
Lenovo (laptop): 
 ThinkPad X1 Extreme Gen 3
 Processor: Intel(R) Core(TM) i7-10750H CPU @ 2.60GHz 2.59 GHz
 Installed RAM: 32.0 GB (31.8 GB usable)
 System Type: 64-bit operating system, x64-based processor

My problems with FireFox 113.0.2 started when I began to download some Affinity V2 videos. Some of these were rather large (over 500MB) and I noticed that several were being downloaded at the same time (which was no surprise). However, after sometime I noticed that only one of the videos was completely downloaded and the others were just stopped. Then, when I looked at the task manager the number of FireFox instances was increasing: ...,5,6,...18,..

Of course, I thought I could fix the download process but all my efforts failed; e.g. after a restart of windows and execution of FireFox the same videos were still in a "hold" state and many instances of FireFox were being executed. After a frustating night of failures I finally decided to restore an older FireFox using my Acronis backup/recovery software. My last Aronis backup of my entire system was made on 2023/04/07 with the most recent version of FireFox at the time which worked fine when downloading several large video files at the same time.

I only included the C:\Program Files\Mozilla Firefox' in the restore since I have installed a rather large number of new apps and updates after 2023/04/07. This also failed -- my add-ons, bookmarks, etc. in this restored version were all missing and before I could stop the recovery process, the restored FireFox was updated to the latest as of today (2023/06/01). And of course the problem had not be fixed.

So finally to my request: What directories, files do I need to restore, from the 2023/04/27 backup with all of its features at that time -- this is important, and how do I stop it from upgrading to a newer version?

I would be glad to provide additional information if needed :-)