wifi connection acting weird

Since a few weeks now (maybe due to new iOS update or phone is compromised), my wifi connection is acting weird. Whenever I'm connected to a wifi network, the connection will work for a few seconds and then nothing. When I go to my settings to check the status of my wifi, I see the wifi button greyed at off while the check mark is still next to the network (as if I'm still connected). The wifi button will always revert to off by itself after a few seconds. The only way to reconnect is to turn on the airplane mode for a few seconds and try to turn the wifi on again. Is it a known problem? Was my iPhone hacked and someone or a malicious program is messing with my wifi settings?

Update 1: I can get a wifi connection, but it is acting weird. I don't want to reset all my wifi passwords as I don't remember them...