In 1.78, I believe the shield value is added to the HP of the Sat, in addition to the damage resistance. If your only firing shield depleters, it will never show the shiles as going down. you either destroy the sat, or is shows no damage, even thos it's "virtual" HP are decreasing... I think
When i was playing 1.78 I managed to destroy shielded Sats. the shield depleters looked like they were doing nothing. not sure if they were or not, so I switched to a weapon that could hit them, and took them out.
Also, I agree, it may have been more than one sat. I have yet to see an AI only launch one of those.
I assume your in tactical combat, which is not available in PBW games, so nothing is relevant with that.
It maked shields on a sat way over powered if depleters don't work. the cost of the shield vs combined damage resistance (300+40) makes it a cheap component (8.5 DR per KT used).
Upgrade to the new patch and see if it makes a big difference. (would like to know myself if they really fixed it

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