Firefox uninstalled without explication on a new Android

I bought a new phone (samsung galaxy s9+) like 3 days ago 23/10/2019 and I didn't installed any app except for FIrefox which I install the first day of the purchase but today when the phone did a software upgrade the FIrefox app wasn't installed in my phone, I looked for it in "setting-->apps" and nothing, the app wasn't there. I haven't downloaded anything on my phone, even I deleted whatsApp because I had it installed in my older phone, I lost my bookmarks which for me it's the important thing. How can this be possible? Will the upgrade be the guilty of this failure? or what's happening here? Is there a way to recover my bookmarks?