Failed: 502 Bad Gateway When Uploading Photos In Galery

Hello, I have the error message Failed: 502 Bad gateway when I upload photos in Galery.

I erase the pictures and start over, I still have the same error.  Some pictures pass and other fafiled. The pictures are good. It's the second time I have the this week on 2 different galery.

I contact Netfirms support, and  they say that it's ok on they side

How could you help me ? Thank you

The issue is on the hosting side of things. Of course the host always blames something else. 

The 502 Bad Gateway error is an HTTP status code that occurs when a server acting as a gateway or proxy receives an invalid or faulty response from another server in the communication chain.[1] This error indicates a problem with the communication between the involved servers and can result in disruption of internet services. The 502 Bad Gateway error is considered one of the most common error codes on the internet and can occur in various scenarios.

Thank you, I get back to hosting