I made a 1.19.2 modpack with a lot of mods in it, and it works in singleplayer. However, when I try to connect over LAN or when another computer tries to connect to me over LAN, the connecting device get's the message "Invalid player data" on their game, and the host will see that the player left the game in the chat before the player ever connects.
After testing a modpack with just Epic Fight and WOM + 1-2 mods at time, I have narrowed it down to a few mods, but there are more mods, as removing those mods does not fix the issue in the entire modpack.

(The name in parentheses is the author name that shows up in curseforge)
The following mods cause LAN connectivity issues:
"EEEAB's Mobs" (EEEAB)
"EpicSoulsBosses" (Shezarrin)

The following mods will crash the game when attempting to connect over LAN:
"L_Ender's Cataclysm" (mcl_ender) or "Citadel" (sbom_xela)

A following mod combinations cause LAN connectivity issues:
"Architectury API (Fabric/Forge/NeoForge)" (shedaniel) + "Epic Fight - Guandao Moveset" (namelesslk)

Even when removing these mods from my entire modpack, connectivity issues still occur.
Here is a list of mod I used:
"Epic Fight"(maninthe_home)
"[FORGE] souls-like universe: epic fight addon" (sunwoolove777)
"Akrion RPG expansion" (dragonkrone58)
"Anvil Never Too Expensive" (tinytransfem)
"AppleSkin" (squeek502)
"Archaeology API" (min01)
"Architectury API" (shedaniel)
"Armor Points ++" (CheosTwitch)
"AttributeFix" (DarkhaxDev)
"Better Copper / Armor and Tools" (Anto1_12)
"Blood And Madness (A Bloodborne Inspired Mod)" (Nitespring)
"Carry On" (Tschipp)
"Cataclysm Weaponery" (eyezlevrai)
"Citadel" (sbom_xela)
"Cloth Config API (Fabric/Forge/NeoForge)" (shedaniel)
"Curios API (Forge/NeoForge)" (TheIllusiveC4)
"Devil May Cry Weapons Reborn" (Ciochu)
"EEEAB'S Mobs" (EEEAB)
"Epic Fight - Guandao Moveset" (namelesslk)
"Epic Knights: Shields, Armor and Weapons [Fabric & Forge]" (magistu_)
"EpicFight - Dual GreatSword" (reascer)
"EpicSoulsBosses" (Shezarrin)
"Explorer's Compass" (Chaosyr)
"Fast Leaf Decay" (olafskiii)
"GeckoLib" (Gecko)
"Guns Without Roses" (Lykrast)
"Immersive Armors [Fabric/Forge]" (Conczin)
"Infinite Anvil" (jetpacker06)
"Jet and Elia's Armors" (EpicTehJet)
"Just Enough Items (JEI)" (mezz)
"L_Ender's Cataclysm" (mcl_ender)
"MC Story Mode Armors [Forge / Fabric]" (chronos_sacaria)
"Meet Your Fight" (Lykrast)
"Mouse Tweaks" (YaLTeR)
"Nature's Compass" (Chaosyr)
"No Additional Repair Cost - Anvil" (srrendi)
"Shadow's Formidable Foes: The HeadHunter" (ModsbyShadow)
"Simply Swords [Fabric & Forge]" (sweenuss)
"Sophisticated Backpacks" (P3pp3rF1y)
"Sophisticated Core" (P3pp3rF1y)
"Spit it out" (Mrbysco)
"Weapons of Miracles - epic fight" (reascer)
"When Dungeons Arise - Forge!" (Aureljz)
"You Died" (GoryMoon)
"YUNG's API (Forge)" (YUNGNICKYOUNG)
"YUNG's Better End Island (Forge)" (YUNGNICKYOUNG)

After 2 hours of testing, I'm tired and I would rather it be fixed than to remove a bunch of mods that I want to stay in the modpack.