What is the contact defined between points and inner surface of the shell part? I didn't understand your description below. A beam is defined by these points, and you've given contact definition between end points and inner surface, right? Where is the 3rd point? Does it bisect the beam at the center?
If your requirement is bonded connection, you can also for shared topology available in Discovery and SpaceClaim. If Ansys gives an unexpected solution for a given setup, it's highly unlikely that it is a bug. Probably verify your setup and loading conditions again for confirmation.
Regarding the cylinder modelled as solid, what error does the solver give in failed solution? Kindly provide the error screenshot in your follow up reply. You can view the solve.out file by following this path: