Hi,
I think you had good luck! You might have had a corresponding firmware version which fit the installation file versions of easy-installer or from OS Dowload site for GS290.
I had the same Problem - but your solution di not help! So I went on a long run of troubleshouting.
My 3 GS290 for Christmas presents were all on the highest level of firmware and OS in the moment (October 2021).
At least I found out that the boot.img, which is delivered with easy-installer or on Download site must be older ones. So I took the newest boot.img - and so newest kernel and hardware drivers - and installed it in spite of the delivered from e.foundation. And voila - it worked with the installation manual from the Download site!
Best Regards
Didi