Forum Thread
"reliable partner" bug
Forum-Index → Bug Reports → "reliable partner" bugas in, after you received the partner quest, you might have obtained the shadow clefairy before you hatched an egg. since the clefairy is a level 70 as you mentioned the system will take it as your strongest pokémon.
i think there were some other similar bugs about not hatching a pokémon but it’s still being identified as “hatched”, like in the halloween event last year i think someone caught a shiny retro gastly, but in prof. rowan’s lab it was reported that the professor says “I see you’ve hatched a special-coloured Gastly (Retro)”.