Finally got everything in order!
I'm writing this for anyone who is planning to get PCC from Qatar.
For those who don't have a Metrash2 you have to download it and register yourself. You should have your mobile no registered under your QID.
Everyone has to apply PCC through Metrash only. Paper applications are not allowed. You will not be given at least an appointment number when you go to the CEID. You can apply for your family members through the app as well. However, you'll have to pay 10QR for each PCC. Fill your details and for "issue for", I mentioned as IRCC Canada (i think it really doesn't matter).
For my spouse I got it approved within a day. But for me when I checked Metrash (followup application option) it was mentioned as PCC on hold due to some missing documents. When you click on it you will get a box to upload a document but unfortunately, it is written in Arabic. So with the help of google translator, I found out that I have to upload the "First date of entry". therefore I uploaded the immigration stamp on my passport. But still, after one day, I got the same message. This happened to me 3 times so I didn't want to do it again so went to CEID in Salwa (near to fingerprint office at around 6.30am - no crowd at all). Had a hard time convincing the policeman to get a number, he was telling me it can be done only through metrash and go away. After showing rejected messages finally he gave me a number to talk to another officer. He was nice though ( I really don't remember his name it was something like Abdulnazer, not sure). He asked for my passport and QID and asked me to check metrash tomorrow and come to print the document if it is approved. I got the approval within a date and got it printed nicely and easily.
4. Another issue was my wife came on a business visa at and she converted it to family visa. Because of this, her first date of entry is shown as per his QID which is not the correct one. After printing, I told the same officer at CEID that the dates have to change and showed him the passport. He told me to go to immigration at Gharaffa and to change it from there. At immigration (Gate 2 - Ground floor) I took a number an waited for my turn. At the counter, the lady told me to meet the Captain at the counter 6. For that, you have to take another number and wait. No one told me about a number I went straight away. because of this a police officer was mad at me and scolded me for going (like I should know everything). Anyway, the captain was a cool nice guy. He asked me for my wife's passport and the stamp of the first date of entry. Then he said he changed it in the system but to wait 12 hours and go to CEID again. Next day, I went to CEID and met the same officer. He wrote something on the old PCC and asked me to go the counter and print it again. Everything else was smooth. Pay 10 QR again and you have it ready.
Wish you all the best!