lamda versus lambda

No, they are right. The correct spelling is Lamda: https://en.wikipedia.org/wiki/Lambda :

Unicode uses the (Modern Greek-based) spelling "lamda" in character names, instead of "lambda", due to "the pre-existing names in ISO 8859-7

See also: http://www.danielmoth.com/Blog/lambda-Vs-Lamda.aspx#:~:text=Spelling%20LAMBDA%20with%20a%20%27b,to%20the%20latin%20counterparts%3A%20ΛΑΜΔΑ.

In greek, it write Λαμδα not Λαμβδα.

wow that is great info! this will be great to win some friendly wagers among my math pals, haha.