[GAMEPLAY] Shaco blink (Decieve) invisibilty true sight bug

Had a weird bug occur last game when facing Shaco while playing as morgana. His blink + invis abilty (decieve) made him immune to true sight both from morgana ult and from the ignite while using them before he blinked away. I have looked on the wiki and ingame, and nowhere does it say that his abilities cause him to be immune to true sight while invisible.

Gamemode was all for one.

Now you might say that he jumped out of my ult which caused it to lose the true sight over him, but that isn't the case here, as he still was unable to be seen even with ignite on him on several occasions, and I still heard the sounds that he got stunned by the ult and he was seen being stunned after his invis went out from the ult.

I don't know what caused this bug to appear this game as i've had no problem with true sight on shaco in other gamemodes. I know videos and screenshots help, but I wasn't fast enough to capture those moments.

Edited: Edit: I have watched the replay and saw atleast 1 occasion where shaco should've been revealed but didn't get revealed by morg ult. Other times I saw the shaco did manage to flash while being invisible without me noticing it during the game, but it was noticeable during the replay.

In conclusion I think I overreacted on the magnitude of this problem, as it didn't happen as often as I thought. I think the truesight bug happened once in the game when ulting both shaco and his clone at the same time, and then the real shaco jumped away with his ability (without using flash).