u/3nder47

I bought my Reebok Club C half a year ago. Normally, I used them as my daily shoes, but then I started wearing another pair for a week. After that, I began to notice these bubbles, and yesterday I saw even more bubbles on the side of one of them. I always store my shoes in a place where they are not exposed to direct sunlight or humidity, and this is the first time I've seen these bubbles on a shoe. Is this normal for this kind of model?