If you run a command like:
/give @s minecraft:lingering_potion{CustomPotionEffects:[{Id:19b,Amplifier:0b,Duration:80}]} 1The potion duration listed on the potion is stated as 1 second (20 ticks), rather than the inputted 4 seconds (80 ticks). The actual potion effect time is correct, however. I've tested this for a few different potion effects, and it always seems to be the case no matter which effects the potion has.
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However, we are already tracking this issue, and this report is a Duplicate of MC-98310, which is a report that has not been resolved yet.
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