Sprint name is getting changed, When i move a story to another sprint

[Shadish Kumar]

While switching the user stories in backlog.
When ever we are moving a User story to another team sprint board,the sprint name is getting changed.
Please see the real time issue we are facing:
4 stories placed under Solar Sprint 4.7 is moved to Milkyway Sprint 4.7 back log.
(steps followed:
Change the IT team name to Milky Way at story level
Pushed the stories to project back log
Pull those stories to Milky way Sprint 4.9)
Issue is after this ,Milky Way Sprint 4.9 name is changing to Solar 4.9 under Team Milkyway Backlog.