London is overwhelmed with applications right now as they are processing a load of the backlog from Islamabad (which is at like 30 months or something insane). So a bucket of Islamabad applications have been sent to London. The knock-on effect is that some of London's applications are staying in Ottawa or Mississauga for processing instead. This isn't all that uncommon. In 2012, Stage 1 approval for outland applications was up around 3 months because Mississauga was overloaded. They forwarded a bucket of applications over to Ottawa to help out with the backlog. Once the processing time came down to 1-2 months, Ottawa stopped processing Stage 1 applications.
In the past few months, Ottawa has been in use again, this time with backlog from London. It's a pretty standard thing, and shouldn't affect overall processing times. We'll see on the spreadsheet once those applications come through, but I would expect timelines to be broadly similar, particularly if they are keeping straight-forward applications in Canada.
For those whose applications are or are not staying in Canada, don't stress about it. It doesn't necessarily mean yours is complicated. It could just be one VO's view of your file. It could be that all apps from a particular week went to London regardless. Don't stress about it.
As a rule, ALWAYS send a complete application. Some people don't send police checks or medicals up front, and in my opinion, they are risking having their application returned for being incomplete. Then you lose half your professing fee. If it's on the checklist, then provide it.