New Ability/Spell Shield

Hi everyone

Can anyone tell me if there is a new ability/spell shield that has come out recently (over the last month or so)? Perhaps in the new runes system or something?

I ask cause I main Blitz and the hook is obviously my main go to ability, I have noticed numerous times now of my hook landing but the enemy champ moving perhaps 1m (in game) and then it cancelling. Obviously this is a big deal to me so I always have a look over things to see "why" it happened. But I can't find anything.

One time I tried to pull a shaco, it cancelled as above and he didn't have any of the shield items banshee etc, I tried to ask him what happened but no response before game end.

Another time I was playing against intermediate bots (teaching my wife the game) and it happened again when I landed a hook on Lux, this time it was like level 3 or so and Lux had no full items at all.

So does anyone know what the deal is? Would love to know what to look out for.

Cheers