Solved if loop-block = {var} doesnt work

[Jacknug]

every 15 seconds:
set {var} to a random element of sand,red_sand
loop all blocks in region "Area":
set block at loop-block to a random element of sand,red_sand
wait 5 seconds
loop all blocks in region "Area":
if loop-block = {var}:
set loop-block to air

all of this works except for

loop all blocks in region "Area":
if loop-block = {var}:
set loop-block to air

error message: There are multiple loops that match loop-block. Use loop-block-1/2/3/etc. to specify which loop's value you want.

i cannot find any solutions to this so could i get some help?
[doublepost=1646334125,1646330578][/doublepost]nevermind i fixed it