I just noticed that I can get a bounty but if the guards don't come after me right away, they won't clear it even if I talk with them. If you talk with a guard while you have a bounty, aren't they supposed to try to collect it?

For some reason the guards are just ignoring my bounty, even if I talk with a guard with low disposition. Is this a known glitch, or a mod issue. I searched the UESP and could find nothing on it.

From what I know, the guards bounty collecting is just another greeting and these things work by priority. So, theoretically, if there's another higher priority greeting available, the guards will use it instead of arresting you. See if any of your mods add dialogue to the "Greetings 0" category in the CS.

if you are using ABM, it is caused by it. Guards ignore bounty below 1000, unless they caught you on the act. The guards can still clear you bounty, using the topic clear your name. If the topic is mssing, you could add it using the console