Problem is that semicolon is not allowed in Cookie according to RFC.6265 - HTTP State Management Mechanism and DevTest is generating a ";" when generating session key {{lisa.vse.session.key}}.
Environment
Supported DevTest Environments.
Resolution
In VSI, when a Token is generated it uses a pattern specified in it. You can see the existing pattern by clicking on the person icon as below. If the pattern has a "."(period - it generates any printable character) which is creating the ";" sometimes and causing the issue. Changing the pattern to use "_" or "&" or any other valid character per RFC6625 instead of "." will resolve the issue.