Sounds like the issues from X1 Carbon 6th gen where the only available standby was always-on-standby (Windows-only thing): some patching of ACPI tables has help

Sounds like the issues from X1 Carbon 6th gen where the only available standby was always-on-standby (Windows-only thing): some patching of ACPI tables has helped with that, though Lenovo has since updated the BIOS and restored the usual S3 standby. 7th gen worked out of the box, but I am not sure if that matches t490 or t14 generation (or maybe even t480). The biggest worry for me is putting it in a backpack and the battery causing a fire.