Bug? Updating parameters... ERROR: ValidationError: No updates are to be performed

Trying to specify LogRetention parameter for an app with convox apps params set LogRetention=60 however this will output the following error:

Updating parameters... ERROR: ValidationError: No updates are to be performed.
	status code: 400, request id: c799ea38-a235-11e9-81ca-dd802667464b
error: Script failed: see failed command above

Any ideas?

Here’s a little bit of context

$ convox version
client: 20190704045851
server: 20190529174125 (foo.example.com)

$ convox apps info -a myapp
Name        myapp
Status      running
Generation  1
Locked      false
Release     XXXXXXXXXXX

Anyone?

Update: I suspect the error is due the fact that this is a gen1 app, and the LogRetention parameter seems to be a gen2-only feature.