Guards run through the blocks. They don't disappear. When a player passes them, they react late. I played the same combos in the alpha. There the blocks reacted faster and disappeared completely.
I have also had issues with Masquerade blocks not working as expected, but not quite the way you describe.
When I set a guard patrol path through a masquerade modded holocube, the expectation is that the guard will pause their pathing when it reaches the block and resume it once it triggers. What actually seems to happen is that the guard path is completely broken and it just sits still where it was placed even after triggering the holocube.