Shulkers in boats disappear after entering end gateways

If you ride a boat with shulker in it into the ender gateway, the boat will get teleported but the shulker disappiers. This bug has been already reported (https://bugs.mojang.com/browse/MC-150597) and resolved as duplicate of https://bugs.mojang.com/browse/MC-147715 . The problem is, that it isnt fixed and it still happens in 1.14.3 even though on the site it says that it is fixed. From my testings this only happens with shulkers. Pigs for example go through just fine