I don't think I've ever ordered anything from Jedediah Starr, but I know they have been in business, serving the muzzleloading community, for a long time. I would not hesitate to order from them, if they had something I wanted.
If you have had an actual problem with them, probably the best thing to do is to contact them directly to achieve resolution.
Retailers of all kinds are struggling with unaccountable supply issues right now. My wife and I like a particular brand of chili seasoning that was out of stock in all the local grocery stores for eight months. I finally found it on the shelf again a couple of days ago, and stocked up! Try ordering garden seed, for an exercise in frustration. My early spring garden, here in Florida, should have been planted by now, but I'm waiting for seeds to arrive. The local "feed & seed" store, which is usually reliable, just didn't have them in stock.
Suppliers to the muzzleloading community, even the ones with fancy websites, are often surprisingly small businesses, and the people who run them are people like us. Rumors spread online can do real damage.
Anyway, I would recommend that you decide what you want, and call Jedediah Starr to see if they have it. If you are looking for something specific that you have been unable to find, tell us what it is and chances are pretty good that the forum members can help you get it.
Best regards,
Notchy Bob