Question about Samsung Galaxy S24

For some time now, my s24 has hardly had any reception and wifi calling is also causing problems. Sometimes I can't be reached even though there is reception. A few minutes later it suddenly works again... with wifi calling the same problem, despite great wifi reception I can't be called. I have already exhausted all possibilities with the provider, new SIM card etc. has brought no improvement. With an old mobile everything works perfectly and I can always be reached... is this a known problem?