I'd stay far away from company X. If they are randomly trying to change the deal out of the blue, would you want to be in a deeper relationship with them? Like

I'd stay far away from company X. If they are randomly trying to change the deal out of the blue, would you want to be in a deeper relationship with them? Like the other commenter said, treat this as an incredible compliment. They see the value of your product and want a slice of the pie. Please approach your other potential customers (ie their competitors), and start removing their leverage on you. Best of luck! Good problems to have!