There seems to be a big increase in notification issues with Moto phones.
We were having several issues with notifications on our new (less than 2 mos old) Moto G6’s. Seemed to start with the recent 4-17-2019 Moto Display App update. The Moto team is investigating a possible bug in the Moto Display app. Here’s a thread with some other background information –
Does this sound like what you are experiencing?
The good news – the Moto team has asked for some feedback on the Moto Display app in the reviews in the Play Store. Hopefully they will find the problem and issue a new version soon!