I'm sorry you're having this issue. First, let's make sure your Alexa app and Echo Spot are fully updated. For the app, go to the appstore on your device and search for Alexa, and look for an update option. For the Spot, just say "Alexa, check for software updates."
If that doesn't work, let's disable the Ring skill and start over. In your Alexa app menu, go to Settings > Skills & Games > Your Skills, then scroll to Ring and select Disable. Then set it up again following these steps directly from the Ring website:
Open Alexa. In the upper lefthand corner, you'll see three horizontal bars. Tap them.
In the menu that appears, tap Skills.
On the next screen, search for Ring in the search box.
After you've found Ring, tap the "enable" button.
Next, Alexa will ask you to sign into your Ring account. Doing so will link your Ring account to your Alexa account.
After signing in, you'll be asked to discover devices. Tap the Discover Devices button. All of your Ring devices should appear and be connected to Alexa automatically. If you don't want Alexa to integrate with a particular Ring device, simply tap Forget on the right side.
If none of your Ring devices appear automatically, you can either:
Ask, "Alexa, discover my devices,"
Tap Devices, then tap Discover
All of your Ring devices should appear and connect automatically to Alexa with either method.
I'm having a similar problem that I've posted about. Alexa will only discover some of my Ring devices but not my Ring Floodlight (which was just replaced with a brand new device). I've updated my Echo Show 5 and I've enabled/disabled the skill so many times I can't count. This does not solve the problem. Ring support has not been able to figure this out and they can see in real time what I've got connected. Amazon support just sent out a replacement for the Echo without really doing any troubleshooting. I'm scouring the forum for anything I can find about this. Very frustrating.