This is becoming annoying because I post a lot and they all just take space in my uploaded templates tab

That was happening to me about 4 days ago but not since then. Those were showing up as private templates.

When you look at imgflip.com/my-templates are there any private templates newer than 2 days?

Yes.
Each one of them is a private template.
And I have to delete them all because I can't find the important ones

I had several "Are You Sure" images that were uploaded as private templates when I was trying to make meme comments with that image 4 days ago, but nothing like that happened to me since then. Making memes from uploaded images works ok for me rn.

If the issue keeps happening to you, I suggest sending imgflip.com/feedback to the devs, which may include additional info about your device and browser.

I just tried, not even as a test, but it didn't happen to me.

Here's the latest I see when uploading an image for a meme comment (meme credit to AmericanViking)

Ok, while it does show up, it's very confusing... Also, yes, I did use just a black box. And also yes, this is my phone's wallpaper.