I:R - Sieged Provinces peacing out

[AggaWackTan]

Description of problem
Sieged Provinces peacing out

What game version are you running?
Latest 2.0

What platform are you playing on?
Steam

Please select any/all DLC you have enabled.
Hellenistic world flavor pack, Epirus flavor pack, Magna Graecia Content Pack, Epirus Content Pack

Do you have mods enabled?
No

Please explain your issue is in as much detail as possible.
I sieged all Cappadocia, but they became tributary of Armenia and all their towns became unsieged.

I know this is related to an event but it seems to be a recurring issue that nations with siege provinces can become peaced out through making peace treaties with other nations but this shouldn't happen.

In the screenshot all Cappadocia was occupied but then for some reason became unoccupied. I looked at the diplomacy screen and they had become a tributary of Armenia and I don't even get a CB on Armenia for this.

Steps to reproduce the issue.
If faction of siege provinces submits to another faction their provinces become unsieged. Despite me occupying their land and not wanting this to happen.

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[AggaWackTan]

In the same campaign I occupied Bambyce and straight away there's a revolt. Having just been sieged down it doesn't make sense that they'd rally back with an army when their garrison had just been zero.