The "testforblocks" command returns false(the problem is it changes its current return value) when one part of the blocks are in render distance and the second part is out of it despite the fact that those compared parts are identical(to me, to let the testforblocks command be errorless, it should load the blocks that are even outside of the render distance and compare them in fact instead of returning false, because in its actual condition, some command blocks may run when they shouldn't(just because of the fact that player quits render distance). I can omit this issue using "testfor" command in like a chain before the testforblocks so I make sure the player is in the render distance first, but it makes it definitely more complicated. Well, the cool thing is that in the actual version of this command I can use it to check if some blocks are in the render distance, but for this thing there could be another command(this would actually be really cool if I could check if something is in the render distance with a specified command, so I would do it often while choosing placement for my command blocks, as sometimes the problem of not correct working of someone's project is that the command blocks are out of render and it would be cool if this would be checked with some command(that you would type in the chat) and the testforblocks command would load the two parts of the blocks before comparing them and changing its return value to false(sometimes we want it to be true until a player opens a barrel or breaks some block).