[?Prompt] with a {CALL:x} or any setting with a colon( : ) in it

[Bob_be]

It looks like you have your syntax wrong. Take a look at this post from QMcKay:

Custom Keyboard Codes

As of v4.1.61 we can create Custom Keyboards to use with [?prompt] notation, and a Custom Keyboard Widget is available for Entity Screens. For [?prompt] notation, the syntax is: [?<prompt>;<mask>;<default value>;<flags>;<keycodes>] <prompt> is the question or prompt to display <mask> is a regular expression to define what type of characters (and how many) are allowed <default value> allows for a common value to be pre-entered <flags> lets you define the keyboard type and which buttons …