What gameplay feature is this bug affecting?
Tigon studs

What's the issue? Please include any error messages you receive and as much detail as possible.
Got a Goddess fertility lioness in heat, sent a studding request then browse through the other available tigon studs and clicked on one and straight away noticed 5 of my females with high fertility showing on the lioness selection dropdown list.
Lioness used for the breeding request:
https://www.lioden.com/lion.php?id=794159775382 (Goddes fertility)
Before I sent the request there were no other of my in heat females showing in the dropdown list.

Any links relating to this bug? For example, if a particular lion is bugging, what is the link to that lion?
https://www.lioden.com/lion.php?mid=9048 (king I had a look at afterwards)
All 4 of my lionesses shown in the dropdown selection list:
https://www.lioden.com/lion.php?id=794158540264 (High fert)
https://www.lioden.com/lion.php?id=794158471713 (High fert)
https://www.lioden.com/lion.php?id=794157960271 (High fert)
https://www.lioden.com/lion.php?id=794157889314 (Very Low fert)
Bought lioness used for the breeding request:
https://www.lioden.com/lion.php?id=794159775382 (Goddess fert)

Any screenshots you can provide us with?
I can't provide any screenshot as I don't have an account with an image hosting site.

Please provide us with step by step explanation how this bug happened so we can attempt to replicate it. If it's complex, please include screenshots where possible:
Got a Goddess fertility lioness in heat, sent a studding request then browse through the other available tigon studs and clicked on one and straight away noticed 5 of my females with high fertility showing on the lioness selection dropdown list.
Lioness used for the breeding request:
https://www.lioden.com/lion.php?id=794159775382 (Goddes fertility)

Before I sent the request there were no other of my in heat females showing in the dropdown list.