Thanks for reporting this issue.
This is often caused by the game client not refreshing after the daily reset has happened. For example, if you were in the guild menu just before reset and then contributed after the reset happened, your client wouldn’t refresh so your contribution will be made to the previous week.
I usually close and re-open the game just after reset to ensure everything will go smoothly.
If you didn’t already write a support ticket about this, you can write a support ticket or PM me your invite code here and I can correct your weekly gold contribution to your Guild if you like.