I have not used the machine regularly for a while now so I can't verify its status enough. But I have checked today and cannot reproduce the issue anymore.
Is the verb tense agreement above correct, or should it be have checked and could not instead?
There is nothing wrong with your sentence.
But I have checked today and cannot reproduce the issue any more.
is okay. Personally, I would not say
But I have checked today and could not reproduce the issue any more.
because "could not" is telic and so doesn't sit well with the adverbial "any more". So here's an alternative:
But I have checked today and could not reproduce the issue.
meaning, at the moment that you checked you could not reproduce the issue. It's unsaid whether the issue has returned since.
