Before accessing the sst26 flash, the "Global Unlock" command must me...

Before accessing the sst26 flash, the "Global Unlock" command must me executed, which I do in the sst26 driver.

BUT. re-reading the datasheet, the WREN instruction is required to enable the execution of this command. This was not done.

I have no idea how the driver currently works except by chance. The writes
should never happen at all, the flash is half-enabled!