Your Daily quest activity resets at 5:00 AM your local time, and Guild activity resets at 2:00 AM UTC.
If your local timezone is different from UTC, all activity and titanite earned between 2 AM UTC and 5 AM of your local timezone will not be counted in today's Guild activity. It is counted towards the Guild activities of the previous day.
To avoid this situation, you should neither collect activity and titanite nor upgrade Glyphs during this time period.