[Bug] Values function in fluent API not working

[mahasadhu]

Bug report

What I did

using fluent API to build filter

What I expected to happen

select2 values filled with function's result

What happened

select2 values empty

What I've already tried to fix it

#3192

Backpack, Laravel, PHP, DB version

When I run php artisan backpack:version the output is:

PHP VERSION:

PHP 7.4.5 (cli) (built: Apr 14 2020 16:17:34) ( ZTS Visual C++ 2017 x64 )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies

LARAVEL VERSION:

v7.16.1@dc9cd8338d222dec2d9962553639e08c4585fa5b

BACKPACK VERSION:

4.1.21@187bb0c3ce52ac2bfefeb9cd7518fec27a82ebcc

[pxpm]

Thank you very much @mahasadhu

I'v just written my thoughts about this in your PR #3192

I am going to close this so we keep the discussion only in the PR thread.

Wish you the best,
Pedro