Alola Pokèmon turning into their normal version after trading

[Keala 7]

Alright so, I've been doing some wonder trades recently and I felt like sending away some of the Alola Geodudes I bred. After a while I started wonder trading again by giving other pokèmons, and surprisingly I received some of those Geodudes back (during the trade it was clearly indicated that their OT was me, Keala) with the difference that they were not Alola Geodudes, but instead they were common Geodudes.
 

My suspect was that the Alola Geodudes turned into common Geodudes after the wonder trade, and to confirm it I made a test. I bred another Alola Geodude, I named it "SendThisBack" and after sending it away in wonder trade, I started trading stuff away until I got it back. After some attempts, I finally got the same Geodude back, converted into his common form.

Alola Geodude that I traded

The same Geodude converted into his common form after getting it back

It's a shame that I wasn't able to trade a geodude with the move Spark, since if this conversion were to happen to an A-Geodude with that move, it would clearly indicate that the Geodude was formerly an Alola Pokèmon. I'm also going to test this with different Alola Pokèmons in order to check if this sort of conversion happens only to Alola Pokèmons that have potentially the same moves as their common form or even to Alola Pokèmons with their new moveset.

 

EDIT-1: I tried trading these pokèmons directly with someone but they did not convert, they stayed in their Alola form as intended, I suppose this means the conversion only happens in wonder trade.

 

EDIT-2: Ok so, with the help of the same person, we made two final tests to confirm this bug, the plan was to trade away a bunch of those pokèmons in wonder trade and the other was supposed to try and find one of those to see the result. On the first test, I sent 4 A-Geodudes with the move Spark (which is not something that a normal Geodude can learn), and luckly we were able to find one of those Geodudes. Geodude with Spark
On the second test we did the same thing, just with something more obvious (Alola Vulpix). Normal Vulpix with Powder Snow

[Exfile 2]

i can also confirm this happening, been using wonder trade a lot and I've got a few Pokemon that i suspect were alolan forms of meowth and rattata although i don't have proof of them as i traded them away again but i do have a Vulpix with a bunch of ice type moves and a Geodude with discharge, both of which can't be wonder traded away due to illegal moves.

Geodude and Vulpix

 

[brianwee2012 0]

It was indeed an alolan vulpix when I traded it... I guess it de-alolanises the Pokemon thru wonder trade.  It doesn't do this thru normal trade actually.

I was just wonder trading away some breedjects...

[Marcello 436]

Thanks for this report, it is indeed an issue with wondertrade. We'll need to take down the server to fix this, so we'll do it when we release E17 Public.