Startup disk with macOS Catalina not showing in boot picker with OC 0.7.4

I've been trying to update from OC 0.6.6 to 0.7.4 without any success because when OC 0.7.4 brings me to the boot picker, my start up disk with Catalina is not showing. Never had this problem before and OC 0.6.6 has been working flawlessly for the past year or so. Why bother updating OC, you may ask? I'm starting to reconsider it but facing this problem now, I need to find a solution.

My specs below.

So, I built the EFI folder three times already, including downgrading to 0.7.3 but the problem persists. I followed Dortania's OC Installin Guide to the word and nothing changes. My Windows 10 boot disk (separate SSD) and the Linux Pop_OS! (3rd SSD) all show in the boot picker when using OC 0.7.4.

Yes, Scan Policy is set to '0' in conflig.plist. Checked Bios set up, etc. I checked already threads here and elsewhere where that problem showed up. Could not find any solutions to it.

Anyone facing similar problem? If so, please share your solution.

Thanks in advance.

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Here are the specs:

CPU: Ryzen 7 2700X

MOBO: MSI B450i Gaming AC Wifi

Boot drives:

• Catalina on Crucial nvme 1TB (my main drive)
• Windows 10 on SSD
• Linux Pop OS on another SSD

RAM: 16 GB

GPU: MSI Radeon RX 580 8Gb