If it's not a glitch, then it's poor design. (ILLAOI)
Just attempted to play again an Illaoi. I don't know if it was my game specifically (glitch) but the only tentacles with targeting indicators were the naturally spawning ones via her passive (NOT ones that come from Trial, those weren't showing indicators either) and it seems the autotracking on the ones from Trial is insane, not only is there no indicator so it's inherently harder to dodge them then normal tentacles, but the autotracking and range of them make them slam down with you in the middle of the tentacle without fail. Every complaint about the Trial tentacles also apply to the ones spawned from her ult. Again, if it was a glitch then it NEEDS to be fixed, she isn't fair to play against by anyone other than Gnar or an equivalent ranged champ and sure as hell isn't fun to fight in any facet. If that's her normal kit now, then someone needs to make some changes.