Graph only takes first query (on multi-query)

Hi,

I updated my grafana 6 to 7 and now when i want multiple query or mixed source on graph, Grafana only execute the query on top. If i had more it show 502 bad gateway.

As exemple:
If i enable my 2 query got not graph and 502 bad gateway

if i enable only fisrt query

and if i only put second query but i put it on top

Seems like a bug

it is the same with mixed source

Thank for your help

Could you fix the issue. Im experiencing the exact same thing and I have a deadline soon