Update on my issue:
Wasn't hub. Wasn't AirWatch. Wasn't Apple. Wasn't the devices. Was us!
Turned out, we'd disabled some encryption protocols that didn't meet NIST recommendation on our on-prem servers. That is what totally broke APNS for us. The cipher suites that Apple supports and the version of Windows server we're running supports that are both NIST recommended didn't jive. Once we figured that out, which was difficult since no logs were ever really indicative of that being a problem (kind of... from our end, APNS request sent... silence and darkness from Apple.), we restored the protocols and everything started working again.
Apple supports:
TLS_RSA_WITH_3DES_EDE_CBC_SHA (rsa 2048) - C
TLS_RSA_WITH_AES_128_CBC_SHA (rsa 2048) - A
TLS_RSA_WITH_AES_256_CBC_SHA (rsa 2048) - A
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
Hope this helps someone!
Hello, somone have the same problem with ' Last seen' in version 1903?