Hi! I just upgraded my self-hosted Minecraft Server Soft based Minecraft server from Spigot to Forge, because I needed mods that weren't plugins. After the transfer, I've experienced severely more lag on the server than before. The server console often reports the server running about 2000ms behind, and reports players "moving too fast"
Also on the client side, I have experienced a weird glitch where if I look a certain direction, the FPS tanks tremendously to about half of what it originally was. There isn't anything that should cause this, and sometimes it fixes itself for a few seconds before breaking again. This can also only happen at my own base, which doesn't have anything special that could cause the lag.
How can I fix these issues?