Q. Does any 18th century source state that there was a controversy about Sri Dasam Granth, (also known as Dasam Patshah ka Granth) or Book of the Tenth King?

There is no such source. There is absolutely no evidence from any source in the 18th centurythat claims there has been any controversy regarding the second canon of the Sikhs. There are various types of literature in Sikh History from the 18th century and within them are numerous
accounts of how Sikhi came to fruition. These include Sri Gur Sobha Granth, Mehma Prakash, Gurbilas Patshahi Dasvin, Gurbilas Patshah Chevin, Bansavlinama, Guru Kian Saakhian. Then there are also the Rehatnamas which are related to the sayings of Guru Gobind Singh Ji.
There is not one line within these texts that claims that there was any controversy on Sri Dasam Granth, on the contrary the evidence for the creation, compilation, and status of Guru Gobind Singh Ji’s Banee is very much positive within them