hi yimindaojianada. di ako sigurado sa process pagobtain ng police clearance sa Taiwan, but base sa kwento mo eh seems you have done everything to comply and meet the deadline. i think if valid naman talaga ung reason and really beyond your control, i think you can just email CEM directly to explain and ask for extension, just make sure you provide evidence and documents to support your claim. sa mga nabasa ko dati eh seems considerate naman ang CEM to situations na di talaga maiwasang may konteng delay. i did email CEM twice dati and so far in a week or so eh i got my reply, ngemail ako nun directly to MANILIMMIGRATION @ international.gc.ca instead of via case specific inquiry (link below). hope this helps po and don't worry too much, you're halfway there..
https://secure.cic.gc.ca/enquiries-renseignements/case-cas-eng.aspx?mission=manila