The Autopilot tries to achieve as much profit as possible for you in any case. If Adspert refers to your AdWords budget as “too low”, it means the following: The autopilot could gain more profit by a volume increase. However, due to the set AdWords budget it is not possible to increase the volume further.
Assumed a conversion is worth 10,- EUR to you and the autopilot could set bids in a way that either 10 conversions for 20,- EUR or 20 conversions for 60,- EUR are achieved.
This example illustrates that for the second case a higher CPO arises but the higher volume achieves more profit. Consequently, the autopilot would decide for the second scenario. However, if you have set an AdWords budget of 20,- EUR, this will be impossible and you will generate 80,- EUR instead of 140,- EUR profit.
Learn more about the autopilot and other possible goal settings in Adspert.