Autodiscovery
To use this feature, Topic must be a single word, ex. sonoff and not a compound topic, ex. bathroom/sonoff. If you want/use granular, specific topics, add that to FullTopic instead.
TDM automatically discovers Tasmota devices which follow these FullTopics:
Tasmota default
%prefix%/%topic%/
Tasmota with SetOption19 enabled for HomeAssistant auto-discovery
%topic%/%prefix%/
The FullTopic pattern affects how the LWT topic is constructed and this in turn affects the autodiscovery process. Since TDM doesn't have the option to manually add devices (because it doesn't have to), to make sure that your devices with custom FullTopics are discovered, you must add these FullTopics to config. You can do it using the dialog found in MQTT -> Autodiscovery patterns menu.
As the message says, the two default FullTopics are included, so you only need to add your customized ones. To make sure they are added correctly, simply copy and paste the entire FullTopic from your device config, found in WebUI in Configuration -> Configure MQTT, right by the Save button:
After adding your custom FullTopics, reconnect to broker via MQTT menu in TDM, or simply restart the application.