Mark, Thank you for your patience. Okay, looking at the errors in the browser console when I click outside away from the Yes (because I can select Yes, but the usual action of clicking outside the value to save it is not working - only for that one setting), and the first error is a 404 for this URL
https://www.9watling.co.uk/connectors/index.php
The file exists at that location.
Then the following:
Uncaught TypeError: this.mask.addClass is not a function
onShow https://www.9watling.co.uk/manager/assets/modext/widgets/core/modx.window.js:60
ExtJS 3
onAjaxException https://www.9watling.co.uk/manager/assets/modext/core/modx.js?v=12400ccc:122
ExtJS 3
f https://www.9watling.co.uk/manager/assets/ext3/adapter/ext/ext-base.js:21
m https://www.9watling.co.uk/manager/assets/ext3/adapter/ext/ext-base.js:21
createCallback https://www.9watling.co.uk/manager/assets/ext3/adapter/ext/ext-base.js:21
setInterval handler*n https://www.9watling.co.uk/manager/assets/ext3/adapter/ext/ext-base.js:21
i https://www.9watling.co.uk/manager/assets/ext3/adapter/ext/ext-base.js:21
request https://www.9watling.co.uk/manager/assets/ext3/adapter/ext/ext-base.js:21
request ExtJS
request https://www.9watling.co.uk/manager/assets/modext/core/modx.js?v=12400ccc:637
saveRecord https://www.9watling.co.uk/manager/assets/modext/widgets/core/modx.grid.js:140
ExtJS 16
F https://www.9watling.co.uk/manager/assets/ext3/adapter/ext/ext-base.js:21
addListener https://www.9watling.co.uk/manager/assets/ext3/adapter/ext/ext-base.js:21
ExtJS 26
Want to add that this is only the third site I am trying to set up with utf8mb4. Found the 2 columns Bob’s script said were mistaken in the 2 tables, and have changed them to utf8mb4.