Can a pharmacist replace Medikinet CR with Symkinet MR?

Yes, both medicines are the same form of modified-release hard capsules and your pharmacist can dispense Symkinet MR for Medikinet CR.
The difference is at the level of absorption - in Medikinet CR the second dose of the drug is released 4 hours after taking the capsule, in Symkinet MR - after about 4 hours. This may be a noticeable change for the patient, e.g. in the case of treating children - it is worth agreeing the change with the attending physician.

You can check availability and make a reservation here:

https://www.gdziepolek.pl/produkty/127637/symkinet-mr-kapsulki-o-zmodyfikowanym-uwalnianiu/apteki

I was given Symkinet MR at the pharmacy as a replacement.
It seemed to me that the weaker effect was the nocebo effect, but from what I read, I am not alone. In my case, the noticeably shorter effect of Medikinet CR occurs if I take it without eating a SOLID meal (a sandwich or a bun is not enough).

I also agree with the negative answers, I feel a much weaker effect on the MR Symkinetic than I felt on the CR Medikinet. In addition, when I pour out a capsule, I see that there are much fewer granules than in a Medikinet capsule of the same dose.
Fortunately, the psychiatrist prescribed me only one package of Symkinet MR for a trial (the rest on the prescription I have on Medikinet).

I got Symkinet at the pharmacy for Medikinet, but it works differently. Firstly, it works less well, and secondly, I feel a lot of side effects, at the moment of "descending" I feel dizzy, I feel sick, I feel a huge sensory overload and irritation. I've never had such problems with Medikinet. I don't want to take this medication

I got symkinet MR as a substitute for Medikinet CR, due to the lack of availability in the pharmacy. I can't believe that anyone allowed it as a replacement. I don't feel any effect of the anxiety other than high-level irritation. I don't recommend it and I don't think symkinet should be allowed to be sold as a replacement.

It can't, if by some miracle there is a replacement then in the pharmacy they made a mistake. In some time it may be possible if the manufacturer provides more documentation because there is a difference in operation.

Difference in Operation:
I started taking Symkinet MR released as a replacement for Medikinet CR. In Symkinet, the second phase of release actually works. Early on telling the psychiatrist about how short Medikinet CR worked, he took it as a need to slightly increase the dose, or replace Medikinet with Concerta (which, however, he did not prescribe because it was very poorly available at the time).

To @Piotr:
I've contacted several pharmacists and indeed, opinions are divided. However, from a formal point of view, there are no contraindications to making the switch.

Since this is a new drug, and in addition, the difference in the level of absorption is described in the SmPC - there is no information from neurologists yet on how they treat this type of substitution.

I couldn't use a substitute at the pharmacy. I had Medikinet on my prescription, but the pharmacy didn't give me Symkinet.