When I open Minecraft normally from the launcher for the 1.13 snapshots, the resolution is at an annoyingly high resolution but at normal size (when it normally changes resolution based on window size). When I try to change the resolution settings (and putting slider back to off) this does not change anything, it is still at the high resolution!
BUT, when I leave the slider on (regardless of if I change resolution settings or not), the game fails to launch. Before the recording, when I turned on the output log, the entire application crashed with no crash report. but because the game failed to launch during recording, I can conclude that this is an issue with the Minecraft Launcher due to there being no errors in the log.
If you want, I can record more videos if you want more information on what I think is an issue with the Minecraft Launcher.