We managed to fix it in SB 3.1 by creating a TomcatConnectorCustomizer implementation based on the one given by Hakan54 here https://stackoverflow.com/a/78347946/5468484.

But, since we upgraded to SB 3.2, we movev the solution to use SSL bundles. It is much cleaner and works perfectly. https://spring.io/blog/2023/06/07/securing-spring-boot-applications-with-ssl

So, if ou are using SB >= 3.2, go for the second solution. If you are stuck in <3.2, go for the first one.