Ctrl+T not Working

I have been having a problem with using the Ctrl+T free transform short-cut not functioning for several months now.

It used to work without problem, when I wanted to edit a layer. This would work fine for text layers, photos, groups of layers, etc.

Reproduction method:

1/ Select the required layer

2/Press Ctrl-T

A purple box used to be drawn around the layer and I could then move it, re-size it or whatever.

This has stopped working now. When I press Ctrl-T now nothing happens.

Note: I can use the menu item: Edit > Free Transform

and the purple box shows up.

The menu item reads:

(tick) Free Transform        Ctrl+T

So it is not a show-stopper for me, but a bit of a pain to have to use the menu each time.

I have looked around the internet but there don't seem to be any obvious solutions. I have tried rebooting of course, but this did not fix the problem.

Any help with what to do to fix this would be appreciated.

I am using:

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Edition Windows 11 Home
Version 21H2
Installed on ‎5/‎06/‎2021
OS build 22000.2538
Experience Windows Feature Experience Pack 1000.22001.1000.0

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Device name DESKTOP-KH9DD2L
Processor AMD Ryzen 9 5900X 12-Core Processor 3.70 GHz
Installed RAM 32.0 GB
Device ID BDD2E1A1-B0A7-43F6-BF17-FF4A0010EADB
Product ID 00326-03102-51320-AAOEM
System type 64-bit operating system, x64-based processor
Pen and touch No pen or touch input is available for this display

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4k Philips monitor PHL 438P1

GPU NVIDIA GeForce RTX 3080

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Thanks, JohnE