Hello,

After doing some research, this appears to be a common issue.

Here are some likely causes I’ve identified:
 

1. Integration Misalignment

• Booking.com reservations might lack essential guest data (such as email and phone number), which MEWS and Vostio require to fully process and sync the digital key request.

• MEWS may trigger check-in invitations before the guest profile is fully populated, leading to downstream mismatches.

2. Vostio Activation Timing

• Vostio typically relies on both check-in status and room assignment before allowing key generation. If either step is delayed or unsynchronized, the key may not be created or appear unavailable.

3. API Rate Limits or Sync Delays

• The integration between MEWS and Vostio is not always real-time. Delays of several minutes can make the system appear unresponsive.

4. Mobile App Conflicts

• If guests are not using a supported browser or the correct app, or if Vostio’s SDK is not properly embedded within the MEWS Guest Portal, the digital key feature may silently fail.

5. Hardware or Firmware Issues

• If door locks are outdated or poorly calibrated, guests may need multiple attempts to open the door — even with a valid digital key.
   

Happy to share more - just send me a private message if you're interested.

as above, however for this part: In general, we’re also having ongoing issues with the functionality of the digital keys. The doors don’t open on the first attempts, and after multiple tries, it might eventually work.

As mentioned may be the lack of API being ‘real time’ but… Also have a look at the time settings on your locks and key encoder - Had this exact same battle when I was a GM, with the key encoder updating between GMT and BST and the locks not…. some great user testing there by the lock designers  lol, so we would check someone in at 3 but they couldn't get in to the room until 4 because of time difference between encoder saying start at 3pm and lock saying nooooo, its only 2pm now…. this is often commonly a solution, as even if its a matter of minutes off it can impact guest experience, especially in standalone systems. With digital keys, and standalone lock systems, I would always send my maintenance guy to set the lock times based on the time on an iphone to standardise.

Same for us - when we switch between winter and summer time, we have to manually update the time on each lock.

We do heve the same problem. We are working with the Guest Key of Hotek and always have issues when a booking.com guest check in. He can not acces his digital key, and it also takes often more than half an our before he receives his key. 

Really frustrating! 

What’s the solution? 

Hi ​@Little Jack Boutique Hotel, thanks for raising this here. As per the comments in this thread it is evident you are not alone with this issue. I can see you had opened a case with our Support team regarding this, which has now been closed. Would you mind sharing here what the outcome of your communication with support was? Thank you