Weird Clipping Midtextures

[CaptainToenail]

Does anyone know why this happens in software mode sometimes, but not hardware mode?

First a midtexture that intersects with a sloping ceiling. The midtexture sometimes bleeds through the slope.
https://imgur.com/js8KHAK

Then there are midtextures that bleed into the ceiling on alcoves like these. Again, it only happens on certain lines. On others they render as they should. if you look closely you can see the transparent silver glass texture rendering over the upper texture of the same line.
https://imgur.com/vUweHu8

In every case the clipmidtextures flag is selected. I have also added it to the mapinfo and it still happens.
https://imgur.com/64ytaw5

In some cases the sector light levels are different also which should also prevent midtexture clipping like this.

Is this a bug or am I missing something here? This is with gzdoom-4-7-1.