From what I can tell, your awning is a "manual crank out/in" awning. The tension is applied by the gas struts on the two vertical arms and there is no spring tension inside the roller tube.
I'd suspect that the "zipped back out when the gear failed" was caused by the tension created by the gas struts.
You can download all of the installation, repair/maintenance, parts and technical reference material here:
https://support.lci1.com/solera-hybrid-awning
I do not see a "spring tensioned roller tube" anywhere in the parts manual, assuming this is the correct awning from LCI.
So, no, I don't believe your awning has a spring tensioned roller tube.