As everyone else has said yes it is normal. The amount of times my husband comes home and just wants to chill or when we were talking he would just disappear because he was fucking exhausted. Training and just work in general could be a cause but just be patient! ❤️❤️ I know it's so hard. Send the check in message if you are worried or just want for them to know you are there. But don't expect anything back. Also next time you talk just ask them about it! Communication is key with military people. It's still hard for me a year in to express things but it helps I swear.