This seems to mostly affect the connected glass mod, and removing Dyenamics and friends fixes the problem.

I'm on Neoforge 1.21.1 version 21.1.169, though an earlier version had the same problem.

Dynamics and friends version 1.21.1-2.1.1

Connected Glass version 1.1.13-neoforge-mc1.21

latest log https://bytebin.lucko.me/Ikfm1olQ9P

can you show a screenshot of it?

which ones are they?

Sorry this took so long. This seems to only affect blocks and not glass panes

Affected blocks:
vanilla tinted glass

vanilla stained glass colors:
white
light gray
gray
red
orange
yellow
lime
green
cyan
light blue
purple
magenta
pink

Dyenamics stained glass colors:
peach
florescent
mint
maroon
lavender
persimmon
honey
ultramarine
spring green
rose
navy
icy blue
wine

Block from Connected Glass:
Connecting glass, connecting tinted glass, scratched glass, clear glass

Connected stained glass colors:
all vanilla colors
mint

Connecting Tinted stained colors:
all vanilla colors
peach
florescent
amber
ultramarine

Scratched stained colors:
all vanilla colors
bubblegum
conifer

Clear stained colors:
all vanilla colors
navy

I think that's all of them.

I found the issue, it's due to Fusion loading some models for one of the other DAF compatible mods which you don't have and then breaking itself. I need to work with the Fusion dev to resolve it but until then a "fix" is to install Productive Metalworks.

Ok.
Downloading the other mod worked great! Thank you!

This bug also seems to affect various other connected block mods; I experienced it with Rechiseled's connecting blocks as well. Looking forward to a fix so this can be included in modpacks!