portal texture not rendering properly

when looking at a nether portal block with gui visible a thin white outline will surround the nether portal block, the outline looks more like a gap between the portal block and lets players see inside the portal block in 1.16.

 

the rendering for the portal has changed in 1.16.1 and now this white outline is colourless, the gap between the portal blocks is thinner and less noticeable in the present update