Rm Series replacement remote control not working

My humax remote control's OK button is not working well (a common problem I can see) so searching for a replacement handset led me to this replacement on Amazon, the RM series (not allowed to post external links but there's only one)

Despite promising it would work immediately it doesn't. The power light on the remote lights up when buttons are pressed so the battery & remote seem to work fine.

On the reviews in Amazon section, I've found that it might be due to the Humax not being in Mode 1. Since my OK button on my original Humax remote isn't working I can't use the standard way of resetting the mode (if it needs resetting) by pressing the 0 and OK buttons.

Thankfully those super experienced users here with your many helpful guides has meant I have now installed custom software and the IR package and followed the instructions in this thread to change the mode via the command line.

This is what I've done. I don't really understand how this works too well but it appears that despite setting my Mode to MODE 1, the CURmode has gone back to 0x7f - am I right? Or has this changed successfully and this still doesn't fix my issue?

humax# ir CURMODE MODE DELAY2 MODE1
CURMODE (0x7f)
MODE (0x70)
DELAY2
MODE1 (0x71)
humax# ir CURMODE MODE
CURMODE (0x7f)
MODE (0x70)
humax#

Any advice on either the above or how to get my RM series remote to work, or suggest alternatives? Obviously now I have the web interface working I can use this but I would obviously just like a functioning remote! Thanks in advance!