Inconsistent Performance

I bought a Serie 4 Condenser Dryer for my holiday home in 2018. I was so impressed that when I moved into my new home, I abandoned my Defy and bought another Serie 4. Almost identical except that the "mixed 58 minute load" works like a charm and dries everything to perfection in my holiday home. Here in Johannesburg, the much newer machine (August 2020) is completely inadequate. Even longer cycles sometimes require me to hang things on the line to finish them off. Not really much point having a tumble dryer! I cannot say it doesn't work, it does blow hot air and the drum turns but not a patch on the other one. All I wanted to do was ask a question of Bosch but as with most websites these days, not at all customer friendly and I do not wish to complete a request for service application with all my address details.