Ring Contact Sensors "disappeared" from alexa devices list

Hello, I recently purchased ring security kit and installed the base station and the contact sensors. I linked ring with Alexa and had few routines created based on the contact sensor events. They were working fine. All of a sudden, a week or two back, the contact sensors (which are the only ring devices that was being shown in Alexa) disappeared from Alexa devices list. The timing was almost coinciding with a) expiry of the "free" 1 month ring protect plan b) i added 1st gen contact sensors which i purchased separately on marketplace. I have been with Ring and Alexa support and have done the usual, resetting, disabling & re-enabling the ring skill etc.. But no luck yet. I did find an old post in the community which described the same problem, but without any resolution.