disappearing solar panels

so i built a very tall house that is 1 floor but the roof is like 10m tall and with that much roof i decided to fill the roof with solar panels, i filled 1 side just fine but when i began on the other side i could only fill half of it until they began disappearing, i don't know if there's a limit or it was a glitch or what because it wasn't consistent, sometimes they disappeared right away sometimes they stayed but disappeared when i put another one down next to it. also had the roof falling down a bit when i was building it but i think that was more because of gravity and not being able to have 4 roof tiles tall without anything around it to hold it in place.