We are currently in discussion with the RTR, as the validator implementation has had problems with long-term validations of short-term certificates for some time. We therefore recommend - as also announced by RTR in the presentations - the use of the EU Validator at DSS Demonstration WebApp (europa.eu)

UPDATE:

1. RTR will enforce in May (as long as all tests are ok) a new validator version which will explicitly allow to define "short term living certificates" as in use with Swisscom and disable the "invalid" validation. RTR is considering placing a notice for this change on the website in order to eliminate uncertainties in the use of the validator.
2. Swisscom will set the - conditional - attribute "archivecutoff" in the next versions of the certificate in the next 4-6 months to show that OCSP answers are also valid for "old" (outdated) certificates. With this any doubts should be eliminated with all validators. Such an implementation with adaptation of the documentation, CP/CPS, certificate profile and agreement with the conformity assessment body unfortunately always takes a few months.