It's preseason, and that means changes to League of Legends. Changes, though, bring with them a lot of bugs and unintended interactions. This preseason the bugs seem focused on champion pets, such as Lulu's Pix, or Bard's meeps.
The first intended design for League of Legends' newest champion, Vex, was for her to be a support mage that relies on opening portals for allies and their abilities to go through. The reason Riot abandoned that idea was that it was estimated to be far too much work for a single champion, as all other champions and their abilities, would have to be remodeled to have adequate interaction with Vex.
In preseason for season 12, though, Riot have decided that adding a drake whose map includes portals is a good thing and the consequences should be minimal.
Recently we have seen Lulu's Pix tank tower shots and block skill shots. Now we have something even worse, as there are more of them. Bard's meeps have been seen to block skill shots and tank tower on the Rift. One of the first to notice this was a UK support streamer Bizzleberyy, and his hypothesis is that the hextech drake portals are to blame.
On the league of Legends' subreddit, after lengthy discussions, a theory has resurfaced amongst the community. The hexgates interact with champions by making what's going through it untargetable and unrendered, so what happens is pets just aren't automatically regaining their untargetability status like they are supposed to.
Whatever the case, summoner-type champions are about to get a lot more powerful on the Rift, if these bugs do not get fixed as soon as possible.