Is this related #22241? Please provide an XML example in your case.

This is code example from my case

			<field
				name="catid"
				type="category"
				extension="com_content"
				multiple="false"
				default=""
				size="10"
				label="JCATEGORY"
				description="MOD_SDI_SELART_CATEGORY_DESC"
			>
				<option value="">JOPTION_ALL_CATEGORIES</option>
			</field>

			<field
					name="artids"
					type="sql"
					multiple="true"
					default=""
					size="10"
					label="JGLOBAL_ARTICLES"
					description="MOD_SDI_SELART_ARTICLES_DESC"
					sql_select="id, title"
					sql_from="#__content"
					sql_filter= "catid"
					sql_where="state=1"
					key_field="id"
					value_field="title"
					sql_default_catid=""
			>
			</field>

I try this from module.

I can reproduce this problem but your code doesn't work in order to solve this bug.

I can reproduce this problem but your code doesn't work in order to solve this bug.

Sorry! I forgot add second part of fix. In the same file (see comment SDI)

It is ok now. But the first part of your code should be:

$curfrm = $this->form;
if (is_array($filters)) :
	foreach ($filters as $i => $v)
	{
		$filterval = $curfrm->getValue ($v, $group);
		if (!is_null($filterval)) 
			$filters[$i]= $v . '=' . $filterval;
	}
endif;

If you don't add "if (is_array($filters)) " then you will have a warning: Invalid argument supplied for foreach() in other sql fields, which don't use the "sql-filter".

Someone should include this fix in the next version of joomla.
However, it doesn't work dynamically, meaning it doesn't change the values after the page is loaded, so it is not very useful.

@sdi68 Try with this PR #24755

Closed as having Pull Request #24755. Please reopen if PR didn't fix the Issue.

Why the solution is not implemented in Joomla core file sql.php yet?