Cookie_qwq

cooldown on disable is modified by disable_cooldown_scale in blocks_attacks component. You should use /give @s shield[minecraft:blocks_attacks={disable_cooldown_scale:0}] instead.

The number displayed on the bar is not exactly the original value due to rounding.

Can confirm in 1.21.8, 1.21.9 and 1.21.10

This is not a bug. Are you trying get attention?

Please check https://help.minecraft.net/hc/en-us/articles/4409161646989-How-to-Report-a-Minecraft-Server