I don’t know if an old world in Minecraft Bedrock is causing this issue, but if you walk over the edges of a Sulphur spike or pointed dripstone, it will send you back a few blocks.
How to Reproduce - Place a pointed dripstone or Sulphur spike and walk over it on one of the sides, and it has a chance to send you back a few blocks.
Edit - This was on my realm, and it appears I cannot reproduce this bug on a new world. This realm was created on a version of 1.16 and is glitching to this day.
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