Premise
Can a Devil variant of the Fiendish Spirit summoned by the Summon Fiend spell perform a Grapple as one of its attacks on its turn, and also use its Hurl Fire ranged spell attack?
Per the actions in this creature's stat block, quote:
Multiattack. The fiend makes a number of attacks equal to half this spell’s level (rounded down).
Bite (Demon Only). Melee Weapon Attack: your spell attack modifier to hit, reach 5 ft., one target. Hit: 1d12 + 3 + the spell’s level necrotic damage.
Claws (Yugoloth Only). Melee Weapon Attack: your spell attack modifier to hit, reach 5 ft., one target. Hit: 1d8 + 3 + the spell’s level slashing damage. Immediately after the attack hits or misses, the fiend can magically teleport up to 30 feet to an unoccupied space it can see.
Hurl Flame (Devil Only). Ranged Spell Attack: your spell attack modifier to hit, range 150 ft., one target. Hit: 2d6 + 3 + the spell’s level fire damage. If the target is a flammable object that isn’t being worn or carried, it also catches fire.
The language of the Fiendish Spirit's multiattack specifies that it can make multiple attacks on its turn, but does not distinguish between Melee Weapon Attacks or Ranged Spell Attacks.
If I am to assume that a Ranged Spell Attack is inherently not considered to be an attack for a monster when it is used, I was unable to find that specifically mentioned anywhere, but would appreciate clarity on where I could find this if it is the case.
What I found was the distinction that players who often ask this question for the purposes of using spells that call for a spell attack roll are actually using the Cast a Spell Action, rather than an attack action, which does not meet the criteria of the Extra Attack feature specifying one can make multiple Attacks when they take the Attack action. Meanwhile, the Hurl Fire action is only classified as a Ranged Spell Attack, which to me, reads as a type of attack specifically and thereby fits within the criteria of the Multiattack feature; that being the Fiendish Spirit may make a number of attacks equal to half this spell's level.
Let us assume for this question the spell has not been cast using a higher level slot and has 3 attacks, as the spell is naturally 6th level.
Per the rules on grappling, quote:
When you want to grab a creature or wrestle with it, you can use the Attack action to make a special melee attack, a grapple. If you’re able to make multiple attacks with the Attack action, this attack replaces one of them.
This leads me to believe that the Devil Variant may both Hurl Fire twice and attempt a grapple on a given target on its turn, using its Multiattack feature. Is that the case, or am I missing something?