connection timed out

[alexgmoca]

I have followed the instructions and everything works fine, until after some time using taiga it becomes incredibly slow and this is the only log that says something about it.
Nginx:
2018/09/18 19:33:49 [error] 1338#1338: *354 upstream timed out (110: Connection timed out) while reading response header from upstream, client: x.x.x.x, server: _, request: "GET /api/v1/resolver?milestone=sprint-1-1&project=zalce-sushi-itto HTTP/1.1", upstream: "http://127.0.0.1:8001/api/v1/resolver?milestone=sprint-1-1&project=zalce-sushi-itto", host: "xxxxxxxxxx.com", referrer: "http://xxxxxxxxxxx.com/zalce-sushi-itto/taskboard/sprint-1-1"