I have no success with them in the ground. I have grown them in pots and sit the bulb on grit to help drainage. then feed them well after flowering.
I do love these.

Also try planting the bulb on its side so that water cannot get into the middle and cause it to rot.
The chap who wrote the only book on Frits recommended planting the bulbs with them sitting on good compost, then filling up around the bulb with fine grit. Don't know if that works though, never tried it myself.

Since they are supposed to be summer dormant, you should try keeping them dry then.

I was lucky enough to see these growing in the wild a few years ago. The three most important things I learned about their likes was drainage, drainage and drainage. You can see the photos I took here (note the soil is almost dust)
https://growsonyou.com/AndrewR/blog/31023-bulbs-and-dionysias-iran-in-april-3

You could try using a cactus type soil mixed with regular soil, and put sand around the bulb to help with drainage. I rotate pots in and out of the house based on when they like it dry. My Tigridias have been inside with no water until the end of March when they will go outside.

I mention Tigridias because they like a dry winter situation. On the opposite end, Nerines and Amaryllis belladonnas like a dry summer, so they receive no water then. The soil becomes very dry, but rehydrates easily when the fall rains start. Frits like a dry summer, so if I could grow them, they would be put in a shed for the summer and maybe watered once at the very beginning of July. It doesn't get below 10°C here and many bulbs like Tulips need vernalization, so I can't grow them.

The 'rainy' season is in the spring but it doesn't always happen. Fritillaria reuteri is small but likes damp soil. I tried growing it as a pond marginal but that was a little too wet for its liking