Before Continuing:

• Check you are using the latest version of the mods and its dependencies
• Always include a latest.log if you are crashing
• Remove known hacky mods such as: Optifine, Fabric API/Connector on forge, and every kind of hybrid server like Mohist and Velocity. None of these are supported. Also try without other lesser usual suspects like Sodium and Lithium.
• If you are unsure which mod is the culprit.
  Disable all of your mods and enable them 1-2 mods each time to isolate the culprit
• Confirm that there is no existing issue with a similar description submitted in the list of issues.

Version

1.21.1-FABRIC

Supplementaries Version

supplementaries 1.21-3.1.7-fabric

Moonlight Lib Version

moonlight-1.21-2.18.16

Describe Issue

When placing non full blocks, such as stairs, slabs, fences, and also from other mods, the texture on the timber frame dissapears where the two blocks stick together.

Also this happens with no other mods on right?

Yes, i did it without sodium, iris, and all other mods, although it's not seen on the screenshot, the framed daub blocks don't have the same issue

Edit: Now it doesn't even load with just supplementaries, it says it requires fabric 1.20.1 or later, but i have 1.21.1

I'm sorry for any trouble, turns out it was a conflict with more culling mod

You should report there