problem with ACF checkbox and the condition to show/hide an image

Hi, i’ve set an ACF field to let check if show an image or another, but when i try to use the dynamic condition I’m having this message

DynamicTag-Value:<br /> <b>Notice</b>: Undefined offset: 0 in <b>…../wp-content/plugins/elementor-pro/modules/dynamic-tags/acf/tags/acf-text.php</b> on line <b>33</b><br /> <br /> <b>Notice</b>: Undefined offset: 1 in <b>…../wp-content/plugins/elementor-pro/modules/dynamic-tags/acf/tags/acf-text.php</b> on line <b>33</b><br />
DynamicTag-Value-Raw:
Notice: Undefined offset: 0 in …../wp-content/plugins/elementor-pro/modules/dynamic-tags/acf/tags/acf-text.php on line 33

Notice: Undefined offset: 1 in …../wp-content/plugins/elementor-pro/modules/dynamic-tags/acf/tags/acf-text.php on line 33

what can I do?

thanks, Emanuele