Changing data tenant

Hello, 

Last year we (Firm based in Germany) switched our Data tenant from Ireland (powerbi.com) to Germany (powerbi.de) and have had issues ever since. 

My question is,  is it possible to switch back to Ireland without losing the data we already have online?

If yes, what does that entail, as I was not present when that switch was made.

Your feedbacks are greatly appreciated 

Afiz