Unavailability of services in EKS

tl;dr EKS, ingress, certificate is valid -> but services are not available

Hi,

I have few services running on EKS. Furthermore, I've made a setup with Ingress and everything works fine. Those few services are defined with one ingress but on different path. Another thing that I've set up is AWS public certificate that is valid. Using that I've set up DNS and point it to ingress.

Worker nodes for cluster are spot instances that are currently available.

The main problem that I'm having is that for the last three days, those services inside EKS suddenly become unavailable. I've checked my setup multiple times and everything works fine. Is there another thing that could cause those unavailability problems?

When I try to access API of services with correct domain name I get this:

DNS_PROBE_FINISHED_NXDOMAIN

It stays like this for some time (approximately 30 minutes) and then it works again.