I am seeing a similar issue. It started early morning on 4/24 with a message to the effect “there was a temporary issue” accessing the cloud DVR programs. This morning I see that 2 out of 13 of my cloud DVR recorded programs are available to watch while the other 11 show “No data available.” when I click on them. My OTA recordings are available. I see this behavior on 2 different Roku model devices with Sling TV app. All have latest updates and latest Sling TV apps. I also logged out of account, deleted Sling apps, rebooted Roku and reinstalled and logged into Sling apps. No change in behavior. My iPhone Sling TV app works with no issues. Sling appears to have some issue on their end.
I contacted Sling TV support and was told others are not reporting this yet. I find that hard to believe. At least I know I am not the only one having this issue. 😁
EDIT:
Just a follow up. I checked more of my OTA DVR (local storage) content using Roku and I see that some is available and some shows the “No data available” message.
Sling TV app on iPhone has no issue accessing OTA DVR programs.