7i92 firmware issue

Maybe some power or SI issue at the Flash EEPROM?

The firmware has a 5 ms timeout for page writes (3 ms max on the W25Q16)
The erase timeout is 3 seconds (400 ms max on the W25Q16)
so that should not be an issue.

I'll look into the power supply.

SI = serial input ?

Thanks again.

SI = Signal Integrity (fussiest signal would be the clock)

Of course, having a "senior moment".

Mainly for my own records and thinking aloud.......
Switched from the i5 & Realtek NIC to a RPi5. Seems somewhat more solid, can get Mesaflash to write reliably with a 8us usleep instruction around the "sync" instruction. Still thinking the issue is my side, have ordered some "sample" interface chips from Microchip, I'll assemble another board, this time using a reflow oven for the SMD parts. If that doesn't fix it I have a board designed for the OMDAZZ dev board I've used before, SPI just needs upgrading to 16Mb part as it only comes with a 4Mb part.