I have both the MK-XIX and L5 Desert Eagles in .357 Mag. Powders that did not work for me were: Blue Dot & N350.
Powders that I’ve used that work well are AA#9, H110/Win296, and N110. I like the Vhit powders and N110 but doesn’t necessarily do any better than H110 or #9 and it’s harder to find at times. But having options is good. 2400 or IMR-4227 should also work well but I have not tried either of those.
One other that you might try is AA#11FS. It’s a bit slower than #9 and works well in the .429 Desert Eagle cartridge. Hodgdon has data on their website.
I mostly use 14.1 gr. of #9 with a 158 gr. Zero JHP. I have used these bullets interchangeably with Hornady XTP. Both feed and function well.
My other “standard” Desert Eagle load is 16.1 gr. of H110 with the same bullets. It works as well but has a bit more blast and produces nice fireballs.
As noted by others, keep the gun clean and lubed. Be sure the slide rails have oil on them. Also put a drop of oil on the bolt locking lugs and on the bolt cam pin. Use a firm grip when shooting as well. If you let the gun roll back as it recoils it may not cycle as well. Use a firm grip, but no need for a death grip.
I have loaded 180 and 200 gr. bullets for the Desert Eagle as well, but the 158s do what I need. I can shoot larger calibers if I need more power.
Have fun!