Happens to me sometimes. If I read shoujo and like it I'll want more and more of it and get annoyed by bl works. And vice versa. But mostly I'm the same as you. Read more bl than anything else and grow annoyed by shoujo. Depends on my mood. Interest towards other genres will come back in a few months
You are not alone in this. It happens to a lot of ppl.
After i started reading bl since last year, i can no longer enjoy hetero stories. At first i wanted to force myself to read those but then i just gave up and now i only read bl and gl. I wish i could be enjoy hetero stories again but its not that i regret reading bl. But sometimes i just wish I could enjoy my favourite hetero dramas/manhwas again like inused to
Uh it's kinda reverse to me, I first stepped in to manhwa/hua/ga world because of BL and got hooked at first (Ahem, I promise it's because of the plot~) and then I stumbled upon Shoujo and damn I was hooked very fast and started reading whatever I get my hands on before loggin in this website and forgot most of em. Anyways, maybe I'm just overreacting and just a reader with a broad range of preferences anyways, you're not alone in this hahaha.

So, I started to read BL quite recently and I have finished about around 25-30 of this genre. Now, after reading BL, I can not go back to reading Shoujo at all. Why did I loose interest in reading Shoujo? Has this happened to anyone else?