I find that I have plenty of strong emotions, particularly when people experience similar negative events to what I've experienced in the past i.e. the passing of a spouse. In those cases, I can feel very distinct and strong emotions and express sincere sympathy to that person. When I experience a negative event that is new and haven't experienced before, if somebody asks me if I'm okay or how I'm feeling the honest would be that I don't know. It takes me time to process my emotions in such instances. For instance, I didn't have contact with my dad for 20 years and found out through the mail that he had passed a year prior. This was six months ago, and I'm still trying to understand my feelings concerning this.
Even if I do experience strong emotions or sympathy concerning something, I know it doesn't show on my face, but I can ACT and show expressions that NTs would understand to be the expression of emotion. However, if I don't act NT, I'll still feel the emotion, but it won't show on my face or in the inflection of my voice.
I think it's pretty common for autistics to feel strong emotions, but sometimes be thrown a loop that they simply can't make heads of tails of until they take time to think about it and process it.