I’m lead lead dev for s2Member. I’m not aware of a specific problem at this time. However, I am opening an issue here so that we can investigate this also. I will update once we know more 🙂 See: https://github.com/websharks/s2member/issues/321
Please feel free to post any additional details (e.g. ways to reproduce the issue) at GitHub, should you find any further evidence of this being the fault of s2Member.