Wither's and Ender Dragon's bossbar ignore health value changes if boss has NoAI:1b

Wither's and Ender Dragon's bossbar ignore health value changes if boss has NoAI:1b, it's not the case in the raids however.

How to reproduce
1.type

/effect give @p strenght 999999 20

2.summon a wither or go to the end

3.hit wither/enderdragon and watch the bar go down

4.type

/data merge @e[type=wither,limit=1] {NoAI:1b}

or 

/data merge @e[type=ender_dragon,limit=1] {NoAI:1b}

5.hit boss again and see the bar NOT going down

6.type

/data merge @e[type=wither,limit=1] {NoAI:0b}

or 

/data merge @e[type=ender_dragon,limit=1] {NoAI:0b}

and watch the bar go down then instead

May be related to MC-124717