Merge columns whith same name in table panel

Hi all,
I have two set of Prometheus metrics related two different event types but with the same meaning (event start_time, event stop_time, event status[ok/ko] ). Label of event name is different (eventA, eventB).

I made a table panel merging the two set of metrics and renamed them with the same labels but columns remain different for the two set of metrics (see image in attachment).
In previuos version of Grafana (6.x), it seemed to me that colums with the same name were merged together.

How can i obtain correct view?

I used ‘Add field from calculation’ → ‘Reduce Row’ → Last (not null) value to add a new Starttime field.
This workaround works also for other metrics (stoptime , success) but it’s not possible with labels

I gave up,
I used label_replace function in one query so I change label name