Joomla module language file wont work - joomla3.0

Question

I want to follow Joomla best practise but I can't get the module language file working. I've tried everything. I've been through all the Joomla and stack overflow questions and the code I've got seems to match the answers but it won't work :(
I have inside of the files tags in the xml for the module
<folder>language</folder>
under files I have the language def:
<languages folder="language">
<language tag="en-GB">en-GB/en-GB.mod_events_display.sys.ini</language>
<language tag="en-GB">en-GB/en-GB.mod_events_display.ini</language>
</languages>
The language folder and files are present on the server. I've also put copies in the site and the admin language folder just for good measure.
The language file is simple now as I've taken everything out to get it to work:
MOD_EVENTS_DISPLAY="Magazine display"
MOD_EVENTS_DISPLAY_SHOW_EVENT_TITLE_LABEL="Show event title"
It's used int the xml file like this:
<field name="showEventTitle" type="radio" default="0" label="MOD_EVENTS_DISPLAY_SHOW_EVENT_TITLE_LABEL" description="MOD_EVENTS_DISPLAY_SHOW_EVENT_TITLE" class="btn-group btn-group-yesno">
<option value="0">No</option>
<option value="1">Yes</option>
</field>
I've checked the module with language debug and it says that it's loaded the file:
**Loaded** : JROOT/language/en-GB/en-GB.mod_events_display.sys.ini
What started out as a 30 min job to be compatible with Joomla guidelines has turned into a 5 hour nightmare trying to get the system to actually work
Any ideas about what other debugging I could do would be great.
(Joomla 3.8.5 and php 7)

Answer 1

Make a copy of what you have and see if this might work for you.
// <folder>language</folder> // remove this line
<languages folder="language">
<language tag="en-GB">en-GB.mod_events_display.sys.ini</language>
<language tag="en-GB">en-GB.mod_events_display.ini</language>
</languages>
...
<field
name="showEventTitle"
type="radio"
default="0"
label="MOD_EVENTS_DISPLAY_SHOW_EVENT_TITLE_LABEL"
description="MOD_EVENTS_DISPLAY_SHOW_EVENT_TITLE"
class="btn-group btn-group-yesno"
>
<option value="0">JNO</option>
<option value="1">JYES</option>
</field>
And that your language folder is structured like this
language
|__ en-GB
|-- en-GB.mod_events_display.sys.ini
|__ en-GB.mod_events_display.ini
Good luck!