TikTok Subscription Issue

Hello, I'm having a problem with my TikTok account. I can't subscribe to anyone anymore. When I subscribe to someone, my number of subscriptions increases normally, but when I leave the app and come back, my number of subscriptions has gone down again, and when I check their account, I see that I'm no longer subscribed to them.

I even tried with my friend's account. I repeated the same procedure. I subscribed to her, her followers increased, as did my subscriptions, but when I checked her account, her follower count had stayed the same as before, and even though I subscribed to her, she didn't receive a notification that I had subscribed. When I return to my account, my number of subscriptions has gone down again.

So, I was wondering if anyone else had the same problem as me and if anyone had a solution to this issue.

Thank you.