How was it solved?
It appears that the swap is broken and is affecting quite a few accounts. I tried sending 10 HIVE to HE. It never made it.
The hiveblock.com link shows the transfers from HIVE to #Hive-Engine :
https://hiveblocks.com/@leodex
The dtools link shows transactions from HE to Hive-Engine.
There should be a matching HE transaction for each HIVE transaction ... but it isn't working.
There are numerous people getting stuck in this @leodex trap. It looks like it has effected people for 4 days.
Quite frankly, I think that LeoDex should remove its swap tool until it fixes the problem.