Hello,
Thank you for providing more details.
Could you try performing a speed test when the 5G signal drops to see if the issue aligns with a known case, similar to the one described in this thread: Issue with Mobile Network Connection RUTX50 5G n78 Band, which also involved Vodafone as the operator.
Maybe the suggestions outlined in the mentioned topic may offer a solution or at least provide more clarity on the root cause.
Best regards,