I'm not sure my comment is relevant for Evo. If it is:
I think you're still bouncing because your error page is not being found either (make sure it's published).
When you make a new request, the index.php file is run. It contains this line:
$modx->initialize('web');
That initializes the web context. After that, resources in other contexts basically don't exist and throw a 404 file-not-found error. MODX redirects to your error_page on any 404, so if the request is for a page in a different context, you're always going to your error page. If the error page is not found (again, because it's in a different context), you'll just go around in circles until the server stops you.
There are various ways around this with mult-language multi-context sites. I'm not sure which one YAMS uses, or even if YAMS uses multiple contexts (or even if Evo *has* multiple contexts). There are several multi-language solutions for MODX Revolution. The
migxMultiLang extra seems to be very popular.
FYI, there is a newer version of YAMS than the one you have (which I believe had a number of problems):
https://modx.com/extras/package/yams