Eclipse Kanto's website constantly failing with 504 Gateway Time-out

Dear Eclipse Help Desk team,

after we successfully migrated Eclipse Kanto's website to the new infrastructure and domain - https://websites.eclipseprojects.io/kanto/ - the website almost constantly fails to load with the following issue:

It would be great if you could have a look into this one as we had our M2 release a few days back and promotions are on the way hoping/expecting a lot of visitors to the website.

Thanks in advance!