The original subject, as it often happens in many other threads, drifted a bit, but I still see this problem of trying to send faster than one actually can, thus making too many errors at sending the own callsign, is well related to the original subject, as there may not be difficult callsigns but inappropiate morse sending speeds used or poor morse copying skills, inappropiate non standard spelling words used, inappropiate or inexistent spacing between callsign letters sent in morse, inappropiate voice volume used, inappropiate mouth to microphone distance…
And many other variables may affect.
Cheers,
Guru