InDesign Transparency setting always revert to low quality no matter what I do

Hello beautiful Adobe Community!
I'm using a PC with latest InDesign.
I discovered that InDesign's Transparency Flatten will never stay on high quality. Always changes back to Low quality. Even when no document is open or closed.
A business card we always do got rejected because the drop shadows and transparencies are low quality on export. I have tried exporting use Press Quality with correct compression settings. I have tried High quality and I have tried PDF/X-1a2001 (<---this usually always works). No matter what I do it is always low quality on export. It just the transparencies though. Other images are always good vector or raster. I
Thoughts?

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I have tried many different PDF versions. I am missing something. 

Chatgpt AI's thoughts
Since you said “It just the transparencies though” and “flattener always resets to Low,” you're probably exporting to a PDF version that ignores the flattener setting, and the flattening is happening later at low res (either at your RIP or the printers).
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I have reached out to the Pre-Press Technician. But waiting for human response.