Graph doesn't show last 2 hours when using certain Quick ranges

i’m playing around with grafana atm and i observed some strange behavour.

I aggregate some timeline data in an mssql table.
so there is a timestamp, a metric and a value.

When displaying in a graph panel the last two hours display no points on the graph, but the scaling of the graph is correct just empty for these two hours. as soon as i zoom out via double click or the zoom - Button the graph shows the complete set of data. this happens for all the quick time range settings “last x hours” the only settings which displays correct seems to be “today, this week, this month, this year”. “today so far” again doen’t display the last 2 hours.

has anyone experienced this?
I trieds several select variations, converting datetime values to utc by subtracting 2 hours but the problem seems to be persistant.

my query looks like this:

dateadd(HOUR, -2, timestamp) as time
,[server] as metric
FROM [sometable]
WHERE $__timeFilter(timestamp)
group by server, timestamp
order by timestamp