Hi,
Slug translation is part of our pro feature, and we suggest to contact us directly on our website,https://translatepress.com/support/, due to the WP guidelines regarding pro features topics.
However, in the eideea that other users could benefit but the information, I want to suggest the following:
Make sure you have pretty permalinks enabled and working. https://www.ads-software.com/support/article/using-permalinks/#using-pretty-permalinks
You can try to resave them from WP Dashboard –> Settings –> Permalinks.
Also, we recommend choosing the post name structure for your permalinks and the default one for the WooCommerce permalinks. These are the most used on sites because are simple and keep your URL as short as possible. It is the one used on most sites because it’s simple and keeps your URL as short as possible.
The 404 error is treated also on our troubleshooting page -> “404 error when accessing a translated page” section: https://translatepress.com/docs/troubleshooting.
However, our dev team prepare to release a new version that will contain multiple fixes regarding slug translation and how we handle these cases, so it should fix also this case. The new update should be available in 1-2 weeks.
Thank you for understanding.
Best Regards,