I have attempted several times to use Tonic for Trace Detection. The screen shows the bubble effect, but the potion doesn't take effect. Also, the count of that potion does not decrease.
@GloomyHawk thanks for reporting! I took a closer look at your account, and I can confirm that you've used Tonic for Trace Detection Potion recently. It was consumed from your Inventory, and its effects were active. If you run into a similar issue again, force-closing the app and clearing its cache may help.