I was curious about that so tried googling ….

Canadian buses were

• earlier models - I see years like 2018
• at least some were built in a new plant in Canada
• part of the blame was lack of spare parts
• part of the blame was limited range, especially in winter

London buses

• newer. I see years like 2024
• no real winter
• I see articles about a new larger battery to fix range issues
• appeared to have similar problems, including a major recall for fire risk

Maybe London benefitted from newer models and doesn’t get as cold as canada