API call create block - blocks options dropped

Hello,

I tried to create a new block following the API call description here:
https://api.qualtrics.com/reference#create-block

The call description shows this data, including Block Options:
'{
"Type": "Standard",
"Description": "My Block Name",
"Options": {
"BlockLocking": "false",
"RandomizeQuestions": "false",
"BlockVisibility": "Collapsed"
}
}'

Following this, the new block gets created but without the Options set (plus there is extra item 'SubType': '').

Can someome please cast some light on why the Options are not reflected in the newly created block? Updating a block via PUT method, the Options set works.

The attached Python code shows what I tried (needs to have API access token filled in).
Oh, actually can't attach a Python code to this post for the .py format is not supported, so providing the code here:
https://gist.github.com/zdenekmaxa/a5001b19ffe621aa247e4a13b4ed7b08

Thanks for your answers,
Zdenek