Obviously, I imagine you already checked cron jobs.
No one can tell you, but whenever you have an issue and you're wondering "what the hell is interacting with my system?" and that part that's problematic (in your case, the deletion of the image) has actions inside of it, we can see what called that specific deletion. So let's see how this applies in your ...
Do you want changes in this :--- get_field('4', $term->term_id)
If this get_field('your_acf_field_slug_name', 'term_'.$term->term_id); or get_field('your_acf_field_slug',$term->term_id).
You can use this reference also :--- https://support.advancedcustomfields.com/forums/topic/get-custom-taxonomy-field-value/
// Yours worked Answer
$icon = ...
You're not outputting any attributes besides the src and class. Try using the_post_thumbnail() instead.
<?php the_post_thumbnail( 'post-thumbnail', array( 'class' => 'img-responsive' ) ); ?>
This will include all attributes and supports responsive image markup by default.
(this should be a comment, but my reputation is too low)
Setting jpeg_quality will not disable compression because it does not disable processing. JPEGs will be always compressed, and they are almost never lossless, not even at 100 - it does not stand for "100% original quality".
What happens here, is that WordPress's default image processing does not ...