@saraheagle Can you look at #44257 if its the same Issue?

Yes, it does look the same issue.
I tested it locally but when I add
'catid' => 'STRING',
as Andrew says works for him, I get the 404 error, like we did a few weeks ago.

I then tested with this old code from an old backup and it works perfectly

protected function _buildDataObject()
{
$data = new \stdClass;

	// Build the additional URL parameters string.
	$params = '';

	if (!empty($this->additionalUrlParams))
	{
		foreach ($this->additionalUrlParams as $key => $value)
		{
			$params .= '&' . $key . '=' . $value;
		}
	}

	$data->all = new PaginationObject(\JText::_('JLIB_HTML_VIEW_ALL'), $this->prefix);

	if (!$this->viewall)
	{
		$data->all->base = '0';
		$data->all->link = \JRoute::_($params . '&' . $this->prefix . 'limitstart=');
	}

	// Set the start and previous data objects.
	$data->start    = new PaginationObject(\JText::_('JLIB_HTML_START'), $this->prefix);
	$data->previous = new PaginationObject(\JText::_('JPREV'), $this->prefix);

	if ($this->pagesCurrent > 1)
	{
		$page = ($this->pagesCurrent - 2) * $this->limit;

		if ($this->hideEmptyLimitstart)
		{
			$data->start->link = \JRoute::_($params . '&' . $this->prefix . 'limitstart=');
		}
		else
		{
			$data->start->link = \JRoute::_($params . '&' . $this->prefix . 'limitstart=0');
		}

		$data->start->base    = '0';
		$data->previous->base = $page;

		if ($page === 0 && $this->hideEmptyLimitstart)
		{
			$data->previous->link = $data->start->link;
		}
		else
		{
			$data->previous->link = \JRoute::_($params . '&' . $this->prefix . 'limitstart=' . $page);
		}
	}

	// Set the next and end data objects.
	$data->next = new PaginationObject(\JText::_('JNEXT'), $this->prefix);
	$data->end  = new PaginationObject(\JText::_('JLIB_HTML_END'), $this->prefix);

	if ($this->pagesCurrent < $this->pagesTotal)
	{
		$next = $this->pagesCurrent * $this->limit;
		$end  = ($this->pagesTotal - 1) * $this->limit;

		$data->next->base = $next;
		$data->next->link = \JRoute::_($params . '&' . $this->prefix . 'limitstart=' . $next);
		$data->end->base  = $end;
		$data->end->link  = \JRoute::_($params . '&' . $this->prefix . 'limitstart=' . $end);
	}

	$data->pages = array();
	$stop        = $this->pagesStop;

	for ($i = $this->pagesStart; $i <= $stop; $i++)
	{
		$offset = ($i - 1) * $this->limit;

		$data->pages[$i] = new PaginationObject($i, $this->prefix);

		if ($i != $this->pagesCurrent || $this->viewall)
		{
			$data->pages[$i]->base = $offset;

			if ($offset === 0 && $this->hideEmptyLimitstart)
			{
				$data->pages[$i]->link = $data->start->link;
			}
			else
			{
				$data->pages[$i]->link = \JRoute::_($params . '&' . $this->prefix . 'limitstart=' . $offset);
			}
		}
		else
		{
			$data->pages[$i]->active = true;
		}
	}

	return $data;
}