Grafana 4.3.1 doesn't pick up newly installed plugins

A brief background leading up to the issue:
I have updated grafana to latest version yesterday. Before updating, I have backed up grafana.ini and grafana.db.
The update went smooth. Grafana restarted without any problems and all my data was intact.
Today, I have installed Influx Admin panel (https://grafana.com/plugins/natel-influx-admin-panel) through grafana cli. After the install, grafana failed to restart. A look into the log file said there is no grafana.ini file. I have used my backup to restore grafana.ini and it helped solve the restart problem.

However, after the restart, grafana doesn’t pick up newly added panels. Under /var/lib/grafana/plugins, I have the following:
grafana-piechart-panel natel-influx-admin-panel savantly-heatmap-panel

Grafana picks up only piechart-panel. I was even able to update the pie-chart panel. The other two does not show up at all.

Is there a workaround for this?

Best Regards,
Kranthi

What does grafana.log say?

Thanks @torkel. For reasons unknown to me, the plugins directory and the plugins within had their ownership changes to root:root. Changing it back to grafana:grafana solved the issue.

Best Regards,
Kranthi