Soil 3 vs 4: relative URLs broken?

[kunstudios]

Hi, I’m hoping someone can help me with this.

I inherited a site that I’m maintaining but I don’t have experience with Roots / Soil.
Soil 3 breaks the interface for ACF (as documented in this forum and the fix is to update Soil) which I did.

But now Soil 4 breaks the filter on this page: https://earnesticecream.com/flavours/#
It works with Soil 3 as shown on the staging site: https://dev.earnesticecream.com/flavours/

Code for the filter is:

<?php $terms = get_terms( 'ice_cream_types' );

if (!empty($terms) && !is_wp_error($terms)){ ?>
	<ul class="list-inline filter-list text-uppercase">
		<?php $count = 0; ?>
		<?php foreach ( $terms as $term ) { ?>
			<!-- Removing Specials and Seasonal from flavour board  -->
			<?php if( $term->slug === 'seasonal' || $term->slug === 'specials'  ):
			else:?>
				<li class="filter-item"><a href="#" class="filter-link <?php if($count === 0): echo 'active'; endif; ?>" data-filter="<?php echo $term->slug; ?>"><?php echo $term->name; ?> <svg class="icon"><use xlink:href="#icon-underline"></use></svg></a></li>
			<?php endif; ?>

		<?php $count++; ?>
		<?php } ?>
	</ul>
<?php } ?>
</div>

I’d love to know how to fix this if it’s a dependency I need to update or tweak the filter code? Any insight would help. Thanks!