Have you experienced this while learning a foreign language?

As a French minor at my university, I’m working my way toward becoming fluent in French. I have noticed that as I gain better command of the French language, I have started to have more difficulty with English. Nothing major, but I might have to really think about something that’s never been an issue before. For example, I might momentarily forget how to spell a certain word or mix up two words. I have to second-guess my writing. I always catch my mistakes so I’m not too concerned about it, but I would never had made the mistakes in the first place until the last year or so. More than anything, I just thought it was interesting that it seems to coincide with my increasing fluency in French. Has anyone else experienced anything similar?