Yes, even a good friend can unintentionally give you feelings of anxiety by behaving in a certain way or saying something that could trigger your anxiety. Or your friend could be toxic, and it's very well masked. It could be anything from constant criticism to competition, deception, exclusion, and manipulation, to count a few. You need to actively see how your body and mind react around them and how your behavior around them is different than with a friend with a healthy friendship. There are signs that you don't feel comfortable around your friend.