Hi audizo,
I also have a Rock Pi 4c+ but didn’t experience the issues that you posted.
I used the imager, got my 64gb sd card (i did order a eMMC but it didn’t arrive in time) I will use dd to transfer to the eMMC once it arrives.
Only real issue I had is that when it first booted the logon prompt did say hit enter, but no usb keyboards were detected. SSH worked fine but I did have a few issues with apt updates but was able to solve them.
Can I ask what power supply you are using, maybe it could be related to this?
Best regards.
Q.