Environment:

Windows 10

baseline:

     76.0RC DE build configured with 1und1 and gmx distribution
     region: de /en-us
     locale: de  / de

modern configuration:

     Fx 78.0a1	20200505094621
     region: de /en-us
     locale: de / de
     simulated distribution id=1und1
     simulated distribution id=gmx
     RS bucket: main-preview

Actual Result:

Comparison betwen 76RC legacy : 78 modern-configuration returns a 10:9 engines, in both unitedinternet distributions listed above.

Expected result:

Not sure if this is a valid bug, since the only difference I see betwen the two engines is the origin param, but IMO I'd expect the two engines to be present in modern-config:
origin=moz_splugin_ff
origin=mc_splugin_ff

Ebay would be also missing from the modern-configuration for the en-us locale in the de region, but that is expected.

Note:

Please also confirm that the different favicon for GMX-Suche is not a issue.

Missed that unitedinternet had 2 more distribution ids. Same missing enginelogic from modern configuration as for the above distribution id's for:

  simulated distribution id=mail.com
  simulated distribution id=webde

The missing engine is from an additional add-on that is shipped with the distribution. We need to test with that add-on installed with the distribution or accept that it is missing.