Can confirm same issue with no great workaround. I started eliminating extra payload key/values and got it to work after removing ones with ISO8601 date strings and empty strings (not null just empty ""). This discovery is still work in progress so I can't say for certain if it was the date or empty strings.
If you have the ability to easily remove/change k/v in your custom payload, I'd suggest doing so to eliminate the offending values. This may not offer a solid workaround since your app could depend on accuracy of those values.
Topic:
App & System Services
SubTopic:
Notifications
Tags: