AITB for telling my spouse not to have heavy discussions right before bed

This doesn’t happen often (like every other month) but sometimes my partner will want to bring up a deep concern right before we go to sleep. I don’t like this, especially during weekdays when we work in the morning. If I don’t get at least 6.5 hours of sleep I will be a zombie and make mistakes at work.

So my compromise is that I will talk as much as they want after work the next day.

They don’t like it as they need to talk about it right now. Even if I’m sleepy and frankly not very useful past listening. They think I’m being dismissive but I’m not. In the past we’ve successfully pushed the topic to the next day or morning if it’s a day off and I felt way more useful.

So AITB for not wanting to have multi hour discussions right before bed?