Hello, I have found a rather interesting "bug". I am not sure if it is one, but max health attributes (using the /attribute command) will not exist after respawning in a single player world on 1.16.1. I was playing a superflat world with the starting configuration minecraft:air. Gamerules doDaylightCycle was false, keepInventory was true, and mobGriefing was false.
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However, we are already tracking this issue, and this report is a Duplicate of MC-179940, which is a report that has not been resolved yet.
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