Hello Andres,
I appreciate the screenshots and the description of when you're encountering this error when working in QuickBooks Online. You've done a fantastic job troubleshooting so far, as those are definitely steps that I would recommend taking to rule out browser, Internet, and device issues causing the error. I'll point you in the right direction for the next steps to resolving this issue.
Since you've already done a good deal of troubleshooting, connecting with the QuickBooks Online support team is the next best step to take. A member of the team will be able to work closely with you to gather details and research this error to learn more about what can be done to take care of it. If needed, they'll also be able to alert the engineering team about it.
There are a few ways to get in touch with support, and you're welcome to choose whichever option works best for you.
Schedule a Callback or Chat: click (?)Help in the upper right > type and enter "Contact support" into the QB Assistant > click Contact Us > explain your situation > click Let's Talk > choose Get a callback or Start a Chat. Support is available from Monday to Friday between 9 a.m. and 8 p.m. ET.
Social Media: Facebook, Twitter, and Instagram.
I notice that your error is partially in French and you seem to be working in a French account. There's also bilingual support available if you'd prefer to speak with someone in French. French phone support hours are from Monday to Friday between 9 a.m. and 6 p.m. ET or you can reach a French agent on social media from 9 a.m to 8 p.m ET.
We're here to help!