Sentinels bugged or am I doin it wrong?

I usually avoid sentinels unless I need pugneum but this last encounter I had was ridiculous. I killed 3-4 of them after stealing some Gravitino balls then of course reinforcements were inbound. I get in my ship and fly off and 10 seconds later an interceptor wa on me. My ship didn't have a good combat loadout and I couldn't escape it so I landed. Of course more ground units came so I started running. 7 minutes later they're still chasing me and I don't even see them. I was even running underground for at least 30s. A message kept coming up saying to destroy them to get a chance to escape so I waited for them to catch up and destroyed them. More reinforcements arrived in like 15s and spawned right next to me. How the hell could I escape that? So I got back to my ship and started looking for shelter because another interceptor was on my tail. I found one quickly before taking any hits and got in. Well, no timer came up, they were still just there, albeit really far away. I pretty much had to stand outside, wait for them to come into visual range, then run back to the shelter and THEN the search timer started. Oh, and more than once my alert level went up without shooting anything, just running around and hiding. Is this how it normally works? Any better way to approach this so I don't waste 20 mins of game time?

Edit: more details about the chase

Update: Having a run-in with more sentinels it seems like behavior has changed (again, maybe bugged). Going underground they didn't follow or attack but also never dispersed. Running into a building without a door (Abandoned Building) doesn't disperse them but they don't attack. I was able to shake them once by transitioning from ship to on-foot (a timer starts every time you transition it seems) then jumping into water before the sentinels arrived. I'm sure it also works to pop out of a hole and defeat every wave but I'm not very into that kind of thing.