Withdrawal from Flex Cash ISA, deposit the same in Stocks and Shares ISA, different provider

Hi, Throughout the `23 tax year I've deposited 20k into a flexible cash ISA, I've withdrawn and redeposited a few times and each time the provider has given me a message on the screen saying my yearly allowance has been adjusted accordingly. I've just opened a Stocks and Shares ISA with a different provider, can I withdraw 2k from my flexible Cash ISA and deposit it into the S&S ISA without any penalties, or do I have to wait until April 6th? When I withdraw the 2k the message will say "you have 18k of ISA allowance left", this leads me to think I can use that remaining 2k in the S&S ISA. Any guidance here? Thanks..

Name removed admin 

*last sentence should say "you have 2k of ISA allowance left"

see SA 12493 

You would need to check if the new stocks and shares ISA is also a flexible one. If not you cannot make any deposit as you have already met your allowance for this tax year

It's not flexible, but maybe I don't see the point in the flexibility of the Cash ISA? I withdraw 2k and am being told I have 2k left of my 20k allowance. The empty S&S ISA tells me I have 20k allowance left, but obv I'll only use 2k until April 6th. I'm confused when you say "you have already met your allowance for this tax year", when I'll have an 18/2 split. I get that I can't deposit into 2 ISAs of the same type over a tax year, but these are different types.