I’ve ran into a big bug when typing lines of text. Every time I turn on the game and try to search maps, prefabs, or gamemodes, use text chat, and do anything else that requires typing, I can only use my keyboard for typing once or twice before it stops working entirely. I can’t click anything with the mouse after this, which can be fixed just by tabbing out of the game. After tabbing out, the keyboard and mouse with work fine during gameplay, but not while doing anything related to entering text. It should also be noted that entering numerical values in Forge seems unaffected by this.
This leads me to a situation where the only way to use my keyboard for typing more than a single line of text is to completely restart the game. This is very cumbersome and is a major deal breaker for Halo 5 on the PC.