Trouble with Rek'Sai Traveling Through Made Tunnels [GAMEPLAY]

Was playing as Rek'Sai today and had trouble traveling through a tunnel that I made. For example, I made a tunnel leaving blue side Gromp into the river bush near bottom. When I was attacked and tried tunneling, I could not go through it. So, is this a bug or you are unable to use the tunnels when being attacked? On the other hand, I made a tunnel leaving golems to red buff and ran into the problem again. After a few clicks in the same spot, it worked.

Unfortunately, I do not have any gameplay to show.