Hi, sorry for short answer before.
I had quite long time discussion with mikrotik about this topic around version 6.25 and maybe also earlier around version 6.17-6.19 if I remember well. This was never enough enlighted by them, but they are still breaking something during they tryouts to make other things better. Sometimes fiddling with "PFS" and "Force AES" setting helped a bit, sometimes the sstp connections needed to be disabled for some time to get it working. It also depends if you are adding IP addresses to the clients by server, as they could be sometimes stated to be invalid on clients side while server looked correctly. Hard to say.
Even I know how problematic and risky is to update to newer versions, I cannot suggest you anything better than to use 6.32.3 and to use l2tp, because you cannot get any support to old versions and I know for sure that with this version it works correctly. At least for me.
Its maybe more safe approach to select one version that is good for you and use it everywhere. And do not touch it until you have real reason to update. Thank make enough tests in laboratory to see the newer version fulfills all your needs and has no hidden bug for you. After that roll this version and be prepaired to get back in case of any problems.