Problems with copy and paste

Before, when I copied and pasted something into my blog or a forum, it just automatically changed to the format of the text that comes before it. So if I were to copy something and paste it after this sentence, it would just look like this text now.

But NOW when I copy and paste, it looks like this (using the title of the January 1, 2025 daily puzzle as an example):

I tested this without Beta and got the same results. I tested this on my alt, which does not have Diamond, and found that copy and paste is normal both with and without Beta. Thus, the Diamond membership is the culprit. Why is it like this? I'm glad someone gifted the membership to me (shoutout to @justelliott61970) and I've already used some of the features, but why does it come with the added problem of not copy and pasting properly?

I drafted this forum in my private club, and I had to rewrite it word-for-word because it wouldn't copy and paste correctly. Point proven.

Copy/Paste will end up with the formatting of the copied text. If you don't want that you should use the paste as plain text option.

I've been using the Paste and Match Style option after this.

But I would like to know why the pasted text (without using Paste and Match Style) is suddenly formatting to whatever format it was in when I copied it, and not to the style of the current text, when on my alt it formats to the style of the current text.

As far as I know, it has always copied the source formatting unless the source didn't have any format to begin with or it was pasted without formatting. Basic accounts may work differently.