Distressing automated email saying I've missed my biometrics window

• On 27 September I submitted my naturalisation application - 20 working days ago.
• The deadline for biometrics laid out on the 'Further actions' page is 29 November.
• My biometrics appointment is tomorrow, 28 October.

I have just received this email from Home Office Atlas <home.office.atlas@notifications.service.gov.uk>:

Following your recent application for Nationality you should have attended an appointment at a UK Visas and Citizenship Application Service point to enrol your biometrics (scanned fingerprints and photograph).

As part of your online application you were informed that you would receive this reminder letter if you had not attended an appointment and enrolled your biometrics within 45 working days. Our records show that you have failed to comply with this instruction, without providing us with a reasonable explanation.

If you have already booked or attended an appointment to enrol your biometrics before seeing this email, then please ignore this reminder.

Next Steps
As part of your online application, you were informed that you have to enrol your biometrics within a specified time frame. You must now return to your online application to book and attend an appointment at a UK Visas and Citizenship Application Service point to provide your evidence and enrol your biometrics (fingerprints and facial photograph).

Your application may be rejected as invalid if you do not provide your biometric information.
This will apply even if you have provided all the other relevant information, documentation and payment required to validate your application.

What happens if I cannot enrol my biometric information?
If there are exceptional circumstances as to why you are unable to enrol your biometric information within the specified time frame you must call the UK Visas & Immigration Contact Centre on 0300 123 2241 and explain why you are unable to attend.  Please be aware that we may request more information and evidence about why you are unable to enrol your biometric features.

I'm really concerned for a few reasons:

• It has only been 20 working days since my application was submitted, but this email is saying it's been 45 (that would be 27 August, not 27 September).
• It says 'you should have' which is implying that my deadline for biometrics submission has passed.
• My deadline for submitting biometrics is 29 November, so why am I receiving this email?
• This sentence is unclear: "If you have already booked...to enrol your biometrics before seeing this email...' I can't understand if it's just saying 'if you're booked, you're good' or if it's saying 'if your booking was before we sent this, you're good'

This is  really distressing because this notification makes it seem like I've missed my deadline for biometrics, despite my application submission date and despite the deadline stated on my 'Further actions' page.

I will of course be calling them first thing in the morning - right after my biometrics appointment, which of course is at 9am same time the UKVICC phone line reopens...