SMS Latency from phone to device?


I’m using a Hologram SIM car in an Arduino MKR GSM 1400, programmed to receive an SMS and display it on the debug serial port. I’ve been using SIM cards from Three (a major carrier in the UK) as well as other global carrier SIM cards and always had a latency of 3 to 5 seconds between sending an SMS from my iPhone to receiving it on the MKR 1400.
However, with Hologram, an SMS takes 10 seconds to arrive. (When I sent it from the Hologram dashboard, it takes 4-5 seconds, but that’s not in my use case)
Is this 10 seconds latency shrinkable? What’s the reason an SMS takes longer with Hologram than other carriers? Is there a way around it?
Thanks a lot