Piano velocity issue with xml imports

In short, why are the velocity levels of the piano LH part consistently louder than the RH part in an xml import and how to I make them the same?

I posted a similar question on facebook earlier in the month rather than here because I couldn’t replicate the problem. I never got a response there. I have replicated the issue several times since then. When importing an xml file I’m running across velocity issues in the LH piano part. Some of the imported files are full orchestra with piano, others as little as 4 instruments with piano. I have reset playback overrides and changed the playback template. I’m not using independent voice playback. I’m not using the pitch contour option. The velocity levels of the LH piano part are always louder than and sometimes double the amount of the RH Piano part. Why? How do I quickly fix the problem? The original music was exported from Sibelius 2022.7 using Dolet 8.1 for Sibelius. In looking at the xml file I see only see a dynamics tag for voice 1, staff 1 and none for staff 2 (not that I would think that should matter since I’m not using independent voice playback). Other than that, there is no dynamics/velocity information in the xml file.

Can you provide us with an example MusicXML file that reproduces the problem?

Dorico doesn’t do anything special when importing keyboard dynamics in MusicXML: it creates them attached to the relevant staff, exactly as you would do when you input them yourself. So dynamics attached to the RH staff will apply also to the LH staff, unless you’re using independent voice playback.

(stripped down dorico project and complete xml attached)
PN-velocity issues.dorico (1.1 MB)

I did some more trouble shooting and may have a solution, but I’m not sure why the problem happened in the first place. I’m not using independent voice playback. I deleted and re-entered all the dynamics and the problem seems to have gone away. It’s almost like the dynamics are being read as voice independent dynamics although I’m not sure I understand why that would make a difference in piano music in this situation. I’m afraid I deleted the problem xml files since I converted it to Dorico and have a PDF backup. I’m having trouble finding the original Sibelius file. If I find any I’ll post the xml and dorico file. (None of this is mission critical. I’m just trying to get old Sibelius created pieces I may never use again into Dorico). It doesn’t seem to happen in solo piano pieces I import, just pieces with other instruments.
Velocity problems.xml (1.1 MB)
(The xml originally had the file extension .musicxml)