veritas 8compact - problem after re-connecting magnetic blocks?

I am having problems with chime function and setting my alarm system. (I have disconnected and re-connected blue wire on magnetic blocks for zone 5 which is my patio door, as I wanted to check what I will have to do when having a new patio door fitted, prior to the window firm coming to my property).

When trying to set part 1 program, zone 3 flashes (correct for this part setting program), but zone 5 light is lit-up but not flashing. I unset the system and checked to see if chime function for zone 5 is active, it is but the panel does not chime when I open the patio door. I have followed the user guide instruction on how to set a zone as chime, this has not worked. I have also tried to re-program part setting program 1 to just omit zone 3 - it seems to work on the setting-up which zones to omit, but when I then try to activate part setting program 1 zone 3 flashes and zone 5 remains constant lit light on the panel.

It is around 5 years since the panel was fitted.