There appear to missing five (5) minute sample intervals/periods for SOAP operation metrics, but none for Services when the metrics are viewed, even if the FxM database is queried directly.
There is no evidence of any FxM restarts.
If there is no activity for the SOAP operation, there will not be any metrics for that interval. FxM does not write out a record if there are no metrics. It is possible to have a Service count of 0 and still have some metrics because there may have been aborted transactions or a transition may have started during that interval and finished in another.
When you are viewing a time range, which does actually data for a SOAP operation count - any 5 minute intervals without data are shown, are having a count of 0 (the second whereas are if you select a time range with no data, then no data is shown.
Services are different because metrics for each sample period have to exist for those hence even if there is no data a row is written to the database.
There might also be cases where a SOAP operation could have a count of 0 but still have other metrics.
None - this is expected behaviour.