It doesn't matter at all, they're synonyms and so they're interchangeable. The both mean the same thing. As duas palavras significam a mesma coisa, portanto você pode escolher qual delas quer usar.

There is no difference between "de novo" e "novamente", in portuguese. Both (adverbs) mean, in english, "again" , "anew" and are interchangeably doesn't matter, which one you use.