The docs say this:
InfluxDB uses a host’s local time in UTC to assign timestamps to data and for coordination purposes.
So I’m not sure if it is saving in Swedish time or UTC time. Both InfluxDB and Grafana expect times to be saved in UTC. If the timestamps are not in UTC, you are going to have to offset the group by time with this advanced group by syntax.
To double check if your data is saved in UTC or not: create a table panel and write a simple select query. Are the values in the Time column UTC or local time? If the dashboard setting is UTC then it should be two hours behind, if the dashboard setting is local browser time then it should be the same as Swedish time.
(you can also use the Query Explorer on the Metrics tab to get the raw epoch values from InfluxDB and convert those to datetime using https://www.epochconverter.com/)