Ahmadiyya are not even considered Muslims among Sunni and Shia.
Even in Pakistan, thy are banned from calling themselves as Muslims.
Primarily, due to Ahmadiyyah's heretical belief that Muhhammad wasn't the last seal of Prophets & Mirza Ghulam Ahmad (1835–1908) was the Mahdi.
No muslim country in the world accepts this denomination to begin with.
Thats indeed surprising that they would have their own parchar stall at vaishaki nagar kirtan. If their stall was approved , atleast basic of sikhi should have been made aware, may be engage in debate, discussion.
On another note- I do find surrey vaishakhi nagar kirtan first time decision of inviting first nations inspiring and fitting though, here its bit of that video:
https://mobile.twitter.com/boparaiied/status/987719594532945920/video/1
Well Sadly, this is the case. No current printed saroop is the same as the Damdami Birh.
These we're not Ram Raiye who made these mistakes while copying Saroops. They had no intent to change the meanings, it just that they inctruduced many human mistakes while copying.
The worst offenders, sadly, are the artistic saroops written during the time of Maharaja Ranjit Singh. Sure these saroops look very nice and are artistic, but most were written by scribes who didn't have Gurbani Vidhya.
I am referring to the various Lagamatra differences.
Another sad this is when panthic scholars try to study Puratan saroops, they are labeled Ram Raiye when in truth they are doing in Good faith to make Gurbani Shudh as possible to the Damdami Birhh.
Books like Paath Beedan Di Sochi by Gyani Gyan Singh Nihung is one example, but because people don't have interest, the book is out of print.
If you are interested in this topic, that book is somewhere on Punjab Digital Library, it shows various variations in Puratan saroops.