I've been unable to duplicate your problem by accessing the 'Find' function through the ellipsis at the top right (although Ctrl F is faster anyway) but whether it matters that you've not got Edge on your computer is entirely a matter for you. I keep Edge on my computer as a back up browser (in case I need to check whether a problem with the display of a website is linked to my choice of browser) but I very rarely use it. Not having it at all wouldn't damage my computer in any way.
My own choice of browser is Slimjet, which is based upon the same 'developer level' browser (Chromium) that powers both Chrome and the latest version of Edge. It's faster and doesn't try to tie you into the services of either Google or Microsoft:
https://www.slimjet.com/