Q:

Why is it telling me that I can't suggest an edit on Meta when I have over 4k rep?

In the above screenshot, It's telling me that I can't suggest an edit on meta - but I have had over 2k for ~8 months.
So why can't I edit this question? Is it because it was merged?

A:

It’s because it’s (basically) locked
You can’t edit the post because it has been merged, yes. Thus the remaining stub post has been locked. 
As detailed here, hovering over a locked post on meta will produce precisely that error. Similarly here.  As mentioned in the comments on the first post, it seems that the system interprets any edit made under less-than-unlimited privileges—including not having the privileges at all—as a suggested edit, for the purposes of throwing errors. 
I can reproduce that error by hovering over the edit button, although I’m not sure why your box is a different color. 

