I have 9 hotspot running Pi-star at the QTH, mixed Raspberry boards and HATs. I do not have this "Not Linked" issue, zero!
At any rate, just because I can - I changed 60 > 1440 > apply changes. 1440 seems to stick but as soon as I moved to Configuration tab and "click" on apply changes button. Then I go back to Expert > YSF GW, 1440 went back to 60 again.
Same thing on the very same page under APRS, I did changed "Enable" from 1 to 0 to disable it, apply changes. 0 seems to stick but again as soon as I went to Configuration tab clicked apply changes, went back to Expert > YSF GW, APRS went back to 1 again.
PS, I know at least 4 friends that are having this YSF "Not Linked" or dropped out after about 1 hr. I see it because I looked at my reflector logs and I see they disappeared from my reflector just about every 60 min or so.
73, Kit