Unfortunately P&W has separate supply-chain issues that are impacting all engine deliveries, distinct from the PW1100G's technical problems.
Nearly half of P&W's suppliers weren't delivering parts on time or meeting quality standards. So the GTF production lines are very underutilized and only a limited number of engines can be made per month until they fix the supply chain.
With hundreds of key suppliers -- some of them probably facing their own supply chain issues -- this is not a problem P&W cans solve overnight. And I'm sure as they slowly get more parts in, P&W is prioritizing PW1100G deliveries for Airbus rather than the PW1500G engines for CSeries.
They should catch up next year but the delays don't help Bombardier obviously.
Over the summer Bombardier execs publicly stated that they expect to announce "multiple" significant orders for the CSeries by the end of this year. There's still time left before the holidays but not much. It's possible that issues at P&W and global events like the Brexit might have had an impact on at least the timing of prospective deals.