After the installation of the Managed Device Upgrade Package, the selector still shows the old version whereas the upgrade package is shown as installed.
The upgrade mechanic is depending on the upgrade package but it is not the upgrade itself. The upgrade will be performed after the policy is processed under the condition that the upgrade package has been processed and identified as "Upgrade OK".
To resolve this issue, ensure that the "Allow removal of this mandatory application after initial installation" setting is not set after the package has been added to a policy. If necessary, edit the package in the policy and ensure that the flag has been deactivitated as shown in the screenshot below.