Bug: Flying zombie offscreen causes game loss

Bug description:

If a flying zombie gets into the "lanes" above or below the lawn, it causes a level to be lost if it reaches the house. More context can be found in the "Additional notes" section below.

Steps to reproduce:

1. Enter the first level of this week's Penny Pursuit, selecting Spring Bean or Boingsetta in the plant selection screen.
2. Wait for a Disco-tron 3000 to enter on the first or fifth row.
3. Use a Boingsetta (preferably by giving it plant food or planting it) or a Spring Bean (preferably giving it plant food) to knock the Disco-tron 3000 above the first row or below the fifth (depending on where it was initially). This should be done while the Disco-tron 3000 has not passed the 9th column so that it is knocked into land instead of falling into water, but not so early that the Disco-tron 3000 has not fully entered the playable area (and thus ignored by the Boingsetta/Spring Bean).
4. Wait for the Disco-tron 3000 to summon a Disco Jetpack Zombie.
5. Notice that this Disco Jetpack Zombie is not killed and will cause the level to be lost when it reaches the house.

Expected results:

The Disco Jetpack Zombie, like all other zombies which are tossed out of playable lanes, should be instantly killed or at least not contribute to a level loss. In comparison, a thrown Imp, while bypassing the water when tossed from a Gargantuar knocked outside of playable lanes in Pirate Seas, still instantly dies when touching the ground.

Observed results:

The Disco Jetpack Zombie flies to the house even while outside of the playable lanes and causes the level to be lost.

Additional notes: 

It is impossible to kill flying zombies outside the playable lanes without Power Toss (even then, it is very hard to physically touch them, as most of their hitbox is offscreen) or instant-kill plants which can reach these areas. This should not be the case as grounded zombies in these lanes, by comparison, are instantly killed, as otherwise players would have no way to defeat these zombies and eventually lose the level. Note that this instant killing applies not only to zombies which simply fall into water in plankless lanes, but zombies which are on solid ground but otherwise near the house (e.g. thrown Imps, as discussed above).

I encountered this while playing the first level of this week's Penny's Pursuit (Food Feud), which is set in Pirate Seas and features Disco-tron 3000s, which summon Disco Jetpack Zombies. By knocking a Disco-tron into the "lanes" (these are outside the board) above the first row (counting from the top) or below the fifth such that it lands on the rightmost part of the lane, it can summon a Disco Jetpack zombie in outside the board which is nearly impossible to kill, as mentioned above.

Because of how difficult it is to reproduce this bug, I could not get another image of the Disco Jetpack Zombie causing a level loss. I did, however, obtain an image of the Imp being instantly killed when outside the map, which is attached to this post.

Edit: I have attached images of the Disco-tron 3000 summoning Disco Jetpack Zombies outside of the playable area and one of the latter causing the level to be lost. 

For reference, I am playing on version 10.6.2, on an iPhone 12 mini.