We have fund issue, that this formula was expecting only 1 label in the issue. Lauma was able to provide solution by following code.
Aggregate(
Filter(
[Epic Link].[Epic].Members,
Generate(
Filter(
[Label].[Label].Members,
([Measures].[Issues created],
[Issue].[Issue].getMemberByKey([Epic Link].CurrentMember.key),
[Epic Link].DefaultMember) > 0 AND
[Label].[Label].CurrentMember.Name <> '(none)'),
[Label].[Label].CurrentMember.Name, ', '
) MATCHES "(^|.*, )MyLabel($|,.*)"
)
)
Thank you Lauma!