I used the "synchronized tabs" feature in the firefox sidebar to open all the tabs that were on my phone on my desktop, they were in total 1193 and this was said by firefox itself(yes i have a lot of tabs open, i moved them to desktop to sort them). Now when they finished loading i noticed a few failed to load, and remain about:blank even though i knew i didnt have any such tabs on my phone, to fix these few tabs i was planning to get a list of urls of all the tabs i opened and a list of those that were on my phone and compare them with a tool online. I got the list of tabs on my desktop through an addon, i checked the number of lines and it matched that that i got from the "syncronized tabs" feature. I got the list of tabs on my android by using the "share all tabs" feature available when you click the three dots on the top right when opening the tabs screen. Once i sent that last list to my desktop i was perplexed, the number of tabs was significantly higher, 1228 to be exact. And when i compared the lists with my online tool the results were even stranger, both lists were missing tabs from the other list, hundreds of them in fact, how is this possible? how do i even know that i got all my tabs if so many are missing from both of these features? Useful screenshot below