MSH makes Minecraft think my modded server is vanilla

[ThatAustinShaw]

EDIT: I started talking with people on the discord server to work through this issue.

Thank you for taking a look at my problem!

My modded server runs fine and all players have no problem connecting when I launch the server by itself, but when I run the server through msh and try to join client-side, it's labeled as an "Incompatible Vanilla server", refusing to let me connect.

The modpack is Better Minecraft (BMC4) from forge. The readme file in the server modpack directory instructs to run a file called "start.sh" rather than running the .jar file directly, so I configured msh-config.json as so:

"Server": {
"Folder": "/home/minecraft/servers/bmc4",
"FileName": "start.sh",
"Version": "1.20.1",
"Protocol": 760
},
"Commands": {
"StartServer": "sh <Server.FileName>",
"StartServerParam": "",
"StopServer": "stop",
"StopServerAllowKill": 10

This seemed to run the server as expected with the hibernating status and all, besides the whole "Incompatible Vanilla server" thing. I've looked through many files in both the msh and modpack directories and I can't seem to figure out what's causing this error. I'm a bit inexperienced with this kind of thing, so any help would really be appreciated!