We have a solution from our webhosting support team, that appears it has indeed fixed a couple of issues on Abantecart. Sharing their response below:
"We’ve reviewed the issue reported on your website and found that it was likely related to PHP’s memory limit settings not properly reflecting on the site.
To address this, we have created a .user.ini file within the root directory of your site and increased the PHP memory_limit to 2048M (2GB). This change ensures that your application has access to more memory, which can help prevent memory-related errors during operation.
At this time, no further errors are appearing in the logs, but we recommend that you test the site and let us know if you experience the same issue again. We appreciate the productive communication with the AbanteCart IT team during this process."