"We will rock you" bug - Every 3rd response empty

The API script is on V8JS, and worked fine, and continued to do so.
About a week back this issue came up where it consistently returned an empty body on every 3rd request.
I’d go to my REST client and keep clicking send for the same endpoint, and every THIRD response is simply blank.
1 - POST /url/api/login
200 OK - { “session token” : … }
2 - POST /url/api/login
200 OK - { “session token” : … }
3 - POST /url/api/login
200 OK -

the headers change too on the failed call;
Date: Sun, 29 Oct 2017 03:32:31 GMT
Server: Apache
X-Powered-By: PHP/7.0.13
X-Frame-Options: SAMEORIGIN
Vary: Cookie
Content-Length: 0
Content-Type: text/html; charset=UTF-8

Date: Sun, 29 Oct 2017 03:32:50 GMT
Server: Apache
X-Powered-By: PHP/7.0.13
Cache-Control: no-cache
X-Frame-Options: SAMEORIGIN
Vary: Cookie
Transfer-Encoding: chunked
Content-Type: application/json

I restarted the server after this and it seemed to have fixed the problem.
Then the issue came back today.

Any idea what’s causing it and how I can prevent it?

“fixed” the issue for the time being by restarting the services via
sudo /opt/bitnami/ctlscript.sh restart

Initially it gave an issue where mysql didn’t start up because of tc.log
So deleted the logfile in /opt/bitnami/mysql/data and started the service - and it started up fine and the issue doesn’t happen.

Still unsure how to prevent this.

[edit a few months later: this keeps happening every couple of months or so, and needs a mysql delete log + restart - is possibly fixed in 2.10]