Is it possible since it only updated to 1809 a few days back, it hasn't scheduled a newer update yet?
You have configured your system to check for feature updates every 365 days.
This machine is running all the time so why is it not updating?
You have configured it to postpone feature updates for 365 days and to postpone quality updates for 30 days.
Based on your settings prior to April 4th, 2020, you were running Windows 10 version 1709, you must have installed Windows 10 version 1709 around April 4th, 2019. KB4537759 was released approximately 30 days ago, for Windows 10 version 1809, on February 10th 2020. Windows is doing exactly what you have configured it to do.
I would still see the new version available and be bugged to install it?
You asked Windows specifically to defer the installation of feature updates for 365 days. Windows 10 version 1909 and Windows 10 version 1903 is only installed if you seek to install it.

Windows Update received some very specific upgrades with Windows 10 version 1903 and Windows 10 version 1909 with regards to how feature updates are installed. So some of the expected behavior does actually happen, however, if you postpone feature upgrades the feature update is still not listed.
You will not be forced to upgrade to Windows 10 version 1909 until Windows 10 version 1809 reaches end of service
Windows 10 version 1709orWindows 10 version 1803prior to April 4th 2020. – Ramhound Apr 08 '20 at 12:40Windows 10 version 1909andWindows 10 version 1903is only installed if you seek to install it. – Ramhound Apr 08 '20 at 12:48