A gif showcasing the glitch
This glitch could have been exploited to go incredibly fast in either direction. This glitch required very specific timing, but was pretty easy despite that. All you had to do to obtain the glitch was just move in the direction you would like to FA towards, and then at the maximum speed, attempt to go the other way. You would've accelerated backwards towards the direction you were in.
This glitch seems to have been caused by the code using Math.abs() somewhere for the velocity.
This glitch was found on July 12, 2021 and patched July 19, 2021