Those broken pipe errors are not your concern. We have them al for over 9 years in our apps. It seems that only recently the cause was found and that in upcoming Mendix versions this error will may be disappear. Now connection bus erros are more likely to be the cause of your problems. I would check your metrics in correlation to the time you first encounter those JDBC errors. What is your app doing at that time? Do you have a lot of connections? Do you run out of thread pool? It is hard to give you advice on this from a distance. There are a lot of pointers in the metrics documentation https://docs.mendix.com/developerportal/operate/trends-v4/
Other sollution would be to get help from the expert service desk of Mendix. But that is paid consultancy but are the real experts on helping trouble shooting your environment.