Hey there 😉 Thank you for this project(The Minecraft).
Although, there's an issue when player can get water teleported and duplicated for some time using Frost Walker and some manipulations showed in video between Water Buckets.
Please, check a video provided which demonstrates an issue.
No mods used. The game is fresh installed.
(Sorry for video's quality, but I compressed it so it would weight 10MB because this site does not allow higher).
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This has the same cause as MC-12363, resolved as a duplicate of that ticket.
Are you sure that this is the same case? Did you notice that water froze even after gathering(at the same time) or vice versa? This might be related.
The same exists in version 20w19a