Being restrained (by a net) gives you disadvantage to melee attacks.
Does that disadvantage also apply to attacking the net with a slashing weapon while restrained by it?
The net says:
A Large or smaller creature hit by a net is Restrained until it is freed. [...] Dealing 5 slashing damage to the net (AC 10) also frees the creature without harming it, ending the effect and destroying the net.
The restrained condition says:
the creature’s Attack rolls have disadvantage.
Attacks on the net with a melee slashing weapon are indeed attack rolls. There is no reason to think that attack rolls against the net are in any way special or excluded from the restriction from the restrained condition.
To avoid that disadvantage, the attack can come from someone outside the net. Or, the netted creature can attempt at DC 10 Strength check without disadvantage.