I do not know if it is just due to snapshots being 'experimental' and generally having lag issues, but as of today I have noticed that movement is a little bugged. However, it is not the normal lag, such as an input delay, but rather the movement continuing for longer than expected.
Scenario: Holding down W to move forward, then releasing W.
Result: Movement continues for much longer than intended, and will not accept any other keys pressed until movement stops.
If this still an issue for you in the latest 1.14 development snapshot, please force a crash by pressing
F3 + C
for 10 seconds while in-game and attach the crash report (minecraft/crash-reports/crash-<DATE>-client.txt) here.