I'm not pushing any particular product so I won't post links. They would get flushed.
Just from personal experience, I've found McAfee, & Norton, to be so-so.
AVG anti-virus & ZoneAlarm firewall have been quite effective.
Have used both for about 10 years (?) & never had a problem.
They have free versions & more robust ones that you pay for. Just Google.
Kaspersky gets good reviews & it does both. Haven't tried it.
Just browsed a number of reviews & they are all over the map regarding who's best.
You
do need both functions. Try AVG & ZoneAlarm. Won't cost you.
If the problem continues, talk to a techie friend.
This site isn't really the place for computer problems but weird stuff does crop up.
Good luck.