For the latest issue in Devops variable , can you try to use lower function to convert the variable value to all lowercase
https://learn.microsoft.com/en-us/azure/devops/pipelines/process/expressions?view=azure-devops#lower
Check out the below articles if that helps:
https://stackoverflow.com/questions/58268287/how-to-lowercase-azure-devops-pipeline-variables-names
If the lower function is not working for you , if you are using some dependent variables , try the alternative options mentioned here:
https://stackoverflow.com/questions/63669006/lower-function-does-not-seem-to-work-in-azure-devops-yaml-pipeline
Regards,
Shiva.