It seems like a repeating command block is active somewhere.
Yes, I can see that.
This is the only block model to have any elements[0].faces.texture not startwith #.
elements[0].faces.texture
#
Can confirm in 1.21.11-pre-4.
That is normal, because if PortalCooldown is greater than 0, entities cannot teleport in a portal.
PortalCooldown
It seems like a repeating command block is active somewhere.