Following the problems with synchronising calendars between the website, Google and your devices, I have deleted the plugin that used to provide a link between the calendars and your phone, so you will need to re-synch your feeds. To do this you need the address of the weekend and extended meets calendar, and to follow the instructions for either iOS or MS Outlook depending on your phone – links below:
Google calendar – Mynydd weekend and extended meets
https://calendar.google.com/calendar/ical/9jvn5tk3tgknquull5qst5qdf8%40group.calendar.google.com/public/basic.ics
iOS integration help
https://support.google.com/calendar/answer/99358?hl=en&co=GENIE.Platform%3DiOS
MS Outlook help
https://support.microsoft.com/en-gb/office/see-your-google-calendar-in-outlook-c1dab514-0ad4-4811-824a-7d02c5e77126
If you use android, just click on the button under the calendar.