I've recently had to block an acquaintance on all social media, thankfully didn't have my phone number.
Similar in someways to OP, acquaintance had different views to myself and was quite negative which brought my own mood down. I live in a small village and we had an informal arrangement that we would meet once a week for socially distanced exercise (walk) during lockdown as we were both in single households and they had seen me out walking and had tagged along.
Lockdown ends, I'm able to return to work full time, the walking arrangement ends, or so I thought.
I was receiving messages almost everyday asking when I could go for walks, explained no time now back at work, replied saying busy another time, etc. I would either be direct and say no not convenient, no I'm no longer going out for walks, or just say I was busy.
Then the acquaintance started knocking on my door, and sending messages (FB messenger) saying I saw you were doing in your sitting room. They would monitor my FB activity and message when I was online.
I ignored the knocks on the door (because they are an invitation to answer not an obligation on my part), and then started the late night drunk messages after closing time as they'd been to local village social club bar. I ignored these too.
In the end I have had to block them as it became so weird and made me feel really uncomfortable in my own home.
I thought I was doing the right thing by allowing it to end naturally with the end of lockdown, but the acquaintance wanted to pursue the non existent friendship.
In hindsight I think a more abrupt end would have saved me stress and worry, and made it absolutely clear I was not interested in maintaining a friendship.
Sometimes people are really thick skinned when they don't want to hear the message you're sending them.
My advice to OP would be if the friend is making you uncomfortable let them know, if it continues just end the friendship as it's not likely they're listening to understand what you're saying and will carry on doing exactly the same things.