How do I permanently hide threads I'm on?

[LittleTipple]

I use MN on my phone and iPad. I regularly hide threads I've been on because they're no longer active or I'm not interested anymore. It works instantly, but a day or so later they appear back on my 'I'm on' list. It's driving me mad - what am I doing wrong?!

Should have said I'm using the app.

@MNHQ

Hi LittleTipple

So sorry for the late response - we must've missed this.
We're not too sure what's going on here so we've flagged to our app developers - someone will take a look soon.

Brill, fingers crossed for an answer!