So I was mucking around with Update aquatic features when I came across this bug.
When you fly in Creative, sprinting doesn't reset when you finish sprinting and stop moving. So a infinite sprint glitch happens. The Sprint doesn't reset until you stop flying. It's really annoying!
Linked issues
duplicates
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Can confirm. Affects spectator mode as well, and creates client-side particles at feet location in spectator mode.
Sprinting does cancel if you stop flying.