In the July 4th release (1.2.2), it says
"minecraft": {
"version": "1.15.2",
"modLoaders": [
{
"id": "forge-31.1.44",
"primary": true
}
]
makes it being loaded as a 1.15.2 Forge modpack in GDLauncher.
I think it should just be a typo or something similar.

Sry I just be idiot

What did you do to fix this? It seems to also be the issue with Twitch...