Okay when you stay on a portal and then hit the arrows/keys the portal becomes unusable, even when you couldn't move in the pressed direction due to water/stones/enemies.

So in short you're still staying on the portal tile, but you can't use it while I think you should be still able to.

Only a small thing since moving away and back again fixes the problem but in times of lag it freaks me out.

Thanks for reporting!

It should be fixed now.

Sorry for the inconvenience.