Foundry v14.365
DnD5e v5.3.3
Vision5e v3.2.0
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Vision Circle is always stays 120 feet even if you have reduced it via Active effect (see Screenshot 2)
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If your Devil's sight let you see through the whole darkness, your ability to see tokens still reduced to your devil sight value. (see Screenshot 3)
As I understand in this case you should just ignore darkness and see everything normally.
Screenshot 1 - 120 feet devil's sight, outside darkness
Screenshot 2 - devil's sight reduced to 60 feet via Active Effect, outside darkness
Screenshot 3 - 60 feet devil's sight, in darkness

Foundry v14.365
DnD5e v5.3.3
Vision5e v3.2.0
Vision Circle is always stays 120 feet even if you have reduced it via Active effect (see Screenshot 2)
If your Devil's sight let you see through the whole darkness, your ability to see tokens still reduced to your devil sight value. (see Screenshot 3)
As I understand in this case you should just ignore darkness and see everything normally.
Screenshot 1 - 120 feet devil's sight, outside darkness
Screenshot 2 - devil's sight reduced to 60 feet via Active Effect, outside darkness
Screenshot 3 - 60 feet devil's sight, in darkness