Well, lets see...
Lambda...╗ - certainly does ... not work...
But MS-Character Map does show them as Λ λ
Ok, lets try the Alt + 955 function ... gives you the ╗
Might have to copy and paste the Lambda symbols below to insert into any document using Forum stripped fonts - I say "stripped" for a reason, they don't have specific characters in which to launch scripts that can become malware - which is more plausible than many realize.
Lambda seems harmless but the Hex code in Python (Linux) can be a disaster example [CODE]Λ or Capital/Uppercase Λ [/CODE] and [CODE]λ Lowercase λ [/CODE] are harmless in ASCII but in machine language - not so much.
Λ λ
Windows can also have corrupted fonts - you have several options...
You can review this link
[URL unfurl="true"]https://appuals.com/how-to-fix-alt-codes-not-working-on-windows-10/[/URL]
When they mention Mouse Keys - doesn't not always fix the problem due to the nature of USB keyboards, or in cases of the Laptops and Tablets that requires the use of an external keyboard - all the available ALT key functions may not work.
If you use 5-pin interrupt keyboard, the one with a dedicated port on the back of the Desktop machine - the interrupt it uses - should allow the ALT function and even the 5-digit ALT keys to input special character sets - to work.