What were you trying to do that didn't work?
MTU settings are sent by the DHCP server on aws. But RHEL-10 keeps 1500 while it is 9001 in RHEL-9.5 and Fedora 40.
Below is RHEL-10 info:

# ip link show eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 0a:c0:1a:23:52:d3 brd ff:ff:ff:ff:ff:ff
    altname enp0s5
    altname ens5
# rpm -qa|grep -i NetworkManager
NetworkManager-libnm-1.47.90-1.el10.x86_64
NetworkManager-1.47.90-1.el10.x86_64
NetworkManager-tui-1.47.90-1.el10.x86_64

Please provide the package NVR for which bug is seen:
6.9.0-0.rc7.5.el10.x86_64
How reproducible:
100%

Steps to reproduce

• start a RHEL-10 t3.small instance on aws

Expected results
the default mtu is 9001

Actual results
it keeps 1500 as default mtu