You included the following in your post:
mqsireportproperties BDSMBRB1 -e ENQ-IIB-RestGateway -o HTTPSConnector -r sslProtocol='SSL_TLSv2'
Does this mean, the expectation is that DevTest must use TLSv2 or TLSv1.2?
The setting you applied only enabled TLSv1. To set TLSv1.2, use this property in local.properties: https.protocols=TLSv1.2,TLSv1.1,TLSv1
If TLSv2 is expected, you may need to contact CA Support as I do not believe TLSv2 is supported as of DT v10.1.