yayyy!!
glad it's fixed now!! ^^
conduit really sucks, but fortunately seems like one of the easier malwares to get rid of

if a browser keeps changing to a default search engine, that's no good 🙂‍↔️

windows defender should indeed take it on it's own, but malwarebytes it's your best second option to check for sure yeah! ^^
if malwarebytes catches nothing, I think you should also run adwcleaner, just to be sure

oh no :(, maybe it's a virus running in the background
I'm no expert but maybe a crypto miner of some kind, best of luck :(