I watch the moons of Jupiter travel across Jupiter whenever possible , fascinating.

All is well, I’m just real busy (a good thing, I guess).

Not sure what camera you are using but some have wide separation between adjacent pixels and have a rather strange grid look. In that case get a different camera. If by “grainy” you mean “noisy” then you just need to stack more images. I typically stack somewhere in the neighborhood of 1500 to 2000 images.

If you are sure your focus is good and you still don’t get any detail, it is almost always because the collimation is not good (in my case that is ALWAYS the cause). It doesn’t have to be off by much either. Laser collimators etc only get you within maybe 3 arc minutes. That is maybe good enough for visual but not for imaging — collimation needs to be within a few arc seconds.

I point at a bright star and then put on the webcam and defocus the star so that I get nice defocused ring. Adjust until it is as symmetric as conditions will permit. It takes maybe a half hour to do the first time, maybe a couple minutes with practice. At the high magnification of a webcam make only slight adjustments. Just enough to move the defocused ring around maybe half a field or less. Differences of adjusting as little as 5 arc seconds are very noticable in the resulting image. (a guestimate assuming the webcam has about 45 arc sec field on my scope).

Always collimate with the same setup that will be used for imaging. If you have an SCT don’t use a diagonal unless its absolutely necessary. Most diagonals are off several arc minutes (even good ones). Any movement of diagonal will destroy the collimation.