MS Store shows an update, but Winget does not

Brief description of your issue

I have Termius installed on my system via Winget.

When I open the Microsoft Store, I can see that there is an available update for it that I can install:

However, Winget does not show any available update, despite msstore being the source, and the installed version being 7.45.1.0 (the same version as listed in the MS Store):

PS> winget list | sls termius

Termius - SSH client                     9NK1GDVPX09V                             7.45.1.0                      msstore

PS> winget upgrade | sls termius

I have updated the msstore source to see if that was causing it, but this update is still not being picked up by Winget.

Am I right in assuming that the msstore source is a mirror of the actual MS Store? I.e. an update visible in the MS Store GUI should also be available as a Winget package upgrade? Or are the updates done slightly differently?

Steps to reproduce

1. Install Termius via Winget (ID 9NK1GDVPX09V)
2. Wait for an update to be available via the Microsoft Store
3. List upgrades either via winget upgrade or check for available versions via winget list | sls termius

Expected behavior

MS Store updates should be visible and installable via Winget.

Actual behavior

They are not.

Environment

Windows Package Manager v1.2.11601
Copyright (c) Microsoft Corporation. All rights reserved.

Windows: Windows.Desktop v10.0.22000.832
Package: Microsoft.DesktopAppInstaller v1.17.11601.0

Start by reproducing the Termius case with ID 9NK1GDVPX09V using winget list and winget upgrade against the msstore source. Compare the reported installed and available versions with the Microsoft Store behavior; done means identifying why the Store update is not surfaced by WinGet or documenting the confirmed source limitation.