download and bookmark import export

The Firefox browser for Android is my number one and primary browser, but since the recent updates (151, 152, and 153), I'm experiencing problems downloading large files or movies. Either the download speed is very slow, or the download fails altogether, even though I have a 5G phone and a 5G network. Another issue is that if I download two or three files simultaneously and then check the file manager within the browser, I only see one file; the other files are hidden. Also, the option to import and export bookmarks is missing, which is a normal feature found in almost all browsers. I've been using Firefox for many years, so please fix these issues.