May 2021 is long time back, so not sure if the same remedicals would work now, as they are valid for only 4 months, which might not be sufficient for them to finalize your application, issue COPR, and for you to personally land in Canada. Therefore, I'd advise you to do medicals again.I submitted a webform to IRCC with the upfront medical information sheet asking them to use it for my IMM1017E.
Can you elaborate on how you requested the clinic to link it at their end, and if they have agreed to do so?
As far as the process for linking medicals by the clinic is concerned, I went to clinic with copy of upfront medical exam sheet done on 18th December 2021 as well as copy of IMM1017E. The clinic kept a copy of both and told me that they will send an email to the High Commission/IRCC (RMO office is my guess) through the emedical system and request IRCC to link my medicals to the new IME number. They said the process can take 7-10 days and advised me to also raise a webform (which I had already done). Hope this helps.