Curious Memory Pressure Alert - SQL Server Process Physical Memory Low

We are, on occasion, out of Sentry, receiving a SQL Server Process Physical Memory Low alert on one of our warehouse instances. The kicker is, I can find absolutely no indication of memory pressure at the time the alert fires.

We are running SQL Server 2019 Enterprise Edition. 256GB of RAM with around 228GB allocated to SQL Server.

Sentry shows 21GB of available RAM for the OS during this whole time. Nothing else is lighting up which supports this alert being real.

Last time this alert fired was 6:02:56 AM this morning. At 6:03AM, system is reporting 21GB available memory.

Thoughts on how I can figure out what is going on here. I could just call it transient and ignore it, but that's just going to bug the snot out of me. :)