Epoch in get parameter cannot be parsed

I have to following issue, we have performance test data in influx and their timestamps are rewritten to be relative from epoch 0. Something weird happens in grafana when I want to see more than a couple of hours on the dashboard. If I go to the timerange dropdown and set from: 1970-01-01 00:00:03 and to: 1970-01-02 00:00:03 the data is plotted nicely and the url get params look like the following:
from=3000&to=86403000 all looks nice, but if I copy this url or just reload the page the from will not be parsed properly and the to becomes Invalid date.
Any idea what is going on? My grafana version is 6.1.6.
The issue is not there if the epoch is small (couple of hours).