Pokemon GO players have been wondering whether Ditto has a bug or has been nerfed. This has been an ongoing discussion in the Reddit Pokemon GO community after one user reported about the said bug.
Ditto is not considered as the strongest Pokemon and the idea that it has a bug that further weakens him is bad news for those who have him. It is also bad news since catching Ditto has never been easy because they are disguised as another Pokemon. For example, you might think its Ratata or Magikarp only to discover that it is Ditto after all.
The said bug was reported by a Reddit user that goes by the name AlexLowrieLifts on the /r/TheSilphRoad community. According to him, he caught Ditto from a Magikarp and a Pidgey. However, when he wanted to power up one of his Ditto's, he was surprised to find out that he has only three candies left.
Some users were helpful suggesting the use of an IV calculator or a similar app to confirm whether he accidentally powered up one of his Dittos. One user said that if the calculator revealed that the other Ditto ends in XX5, chances are, it has been powered up. On the other hand, other users are skeptical saying it hasn't happened to them.
Although there hasn't been any other reports regarding the issue, another user called Illuminiele said that he saw other threads discussing the supposed Pokemon GO bug. He also said that this bug could happen very rarely and suggested some possibilities why.
One of those is a slow Internet connection and the other is when switching between Wi-Fi and mobile data. He also said that the model of the phone you are using could also cause that bug.
Otakukart mentioned that this bug makes a lot of sense because Pokemon GO might have difficulty identifying which Pokemon was caught because of the disguise. Therefore, it refused to give candies altogether.