Is this a particle system issue, limitation or something?

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17/02/2021:

I have make this parterre which consists of three joined objects. I have also create vertex group for its surface so to add grass using “particle system”.
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I plan to repeat it several times into my project, so to make it “lighter” I decided to crack it to quarter and do the job with instances.
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But, when I try to create an instance of collection which contains those quarters instances, I get this…
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For some reason repeats the quarters but not the “particle system”!!!

18/02/2021:

With the help of a member from a Blender’s Greek group, I realized that for some reason “Particle System” only appears correctly with “Rendered” “Viewport Shading” and “Cycles”.

Material Preview & Eevee
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Rendered & Eevee
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Material Preview & Cycles
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Rendered & Cycles
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So, is there a limitation or something???