Hardware that forwards packets usually forwards IP packets, it doesn't care about TCP checksums and doesn't recalculate them. TCP stack in your OS is the one that does that.

It has to be a special kind of hardware that does much deeper packet inspection (DPI) to recalculate TCP checksums, usually used for spying, throttling, censorship, injecting ads, injecting exploits, etc., but not merely routing/forwarding packets.