I noticed that the FMEServerJobSubmitter transformer dialog is missing a button on it, the Refresh Parameters button, which used to be directly under the parameters list in 2017 version (if my memory serves me correctly).
The documentation even refers to it:
As a workspace evolves over time, parameters are added/removed/renamed, therefor this is crucial functionality that needs to come back. My current workaround is to delete the FMEServerJobSubmitter transformer and add it in again (with the added hassle of re-specifying all the settings).
If there's a different way of refreshing the parameters, I would love to know how.