If you are observing a low Push Notification rate for a particular campaign, the first thing you can look out for is a campaign with a similar number of total guests and see the open PN rate for the same.
Also you can run a test to see if you are able to receive a PN or not, here is an article for reference:
How a test Push notification is sent without creating a test Campaign?
In an effort to supply information as quickly as possible, this article has been published prior to a formal technical review, and is subject to factual, grammatical, and various structural errors. Data may be incomplete, misordered, or incorrect.
This additional disclaimer will be removed upon formal review of this article. The standard Punchh Inc. KB Disclaimer still applies, and can be found at: https://support.punchh.com/hc/en-us/articles/360040100273-Punchh-Inc-Knowledge-Base-Disclaimer
If further assistance is required, submit a ticket to Punchh Support. (For help submitting a ticket, click here)