When upgrading the blacksmith, the funding icon no longer popped up. However, I could fund if a guild member shared it to the chat.
Here's a explanation You Said While Upgrading Right Yes If You're Upgrading There's No Icon Even If It's Not on cooldown Or Max Contribution You Can Also Go To Guild And Click The Perk Tab And Fund From There If You're Upgrading Your Perk Building
No, I'm saying the pop-up icon for funding doesn't show up if you are upgrading the building. I hadn't made my max contribution yet and it was available for funding.