Wi-Fi can't access certain websites

My home Wi-Fi can't access certain websites and would forever load until it throws up an error state. When I'm connected via ethernet, it works fine, so I know the Wi-Fi has issues. I also want to add that my printer normally prints via Wi-Fi and lately it hasn't been connecting. I'm having to hardwire my printer to my Macbook.

Notes:

• The devices I'm using are Macbook and Android phone.
• This problem started roughly three months ago. No changes have been made to my Wi-Fi (that I know of).
• I tried changing the DNS. It worked for a day but now the problem continues to exist.
• I've reset the modem/router.
• I've tried accessing aforementioned websites on different browsers. Same problem.