Plan variables not being substituted correctly into build

Appears to be an issue with when repo checkout happens for a build, Bamboo is not reading the correct value of a variable out of the database, it is using an older, cached version of that variable. For ex:

Database value: my.repo.branch = release/2016.7
Plan configuration variable page: my.repo.branch = release/2016.7
Build log:

Substituting variable: ${my.repo.branch} with release/2016.6

The build log shows Bamboo still trying to checkout the old value of that variable. Restarting Bamboo appears to reload all variables from the database and the builds kick off again fine, using the correct release/2016.7 variable.

This seems to have been introduced with 5.10, had no problems with the variable substitution not reading the correct value from the database in 5.9