[BR] Mew (FCO 29). Cottonee (CEC 147). Mew won't let me use lost

Mew (FCO 29). Cottonee (CEC 147). Mew won't let me use lost march even though cottonee is in the discard pile. Not sure If I am reading Mew wrong or if this is a bug.

Game starting
Game type: QuickPlay
Game format: Expanded
Battle started between digocampeao and QuazaTCG!
Coin flip result: HEADS
digocampeao will start
Game setup complete
Between turns
Turn 1 begins
digocampeao drew 1 card
Put Zorua onto bench
[QuazaTCG]: glhf
Attached a Capture Energy (DAA 201) to Zorua.
Put Ditto Prism Star onto bench.
digocampeao has shuffled deck.
Between turns
Turn 2 begins
QuazaTCG drew 1 card
QuazaTCG played Level Ball.
Put [Cottonee (CEC 147)] to Hand
QuazaTCG has shuffled deck.
Put Cottonee onto bench
Attached a Double Colorless Energy (GRI 166) to Cottonee.
Emolga retreated.
Cottonee is now active
Emolga has used Nuzzly Gathering
Put [Emolga (TEU 46)] to Hand
QuazaTCG has shuffled deck.
QuazaTCG played Lost Blender.
Put [Emolga (TEU 46), Jumpluff (LOT 14)] to Lost Zone
QuazaTCG drew 1 card
QuazaTCG played N.
QuazaTCG has shuffled deck.
QuazaTCG drew 6 cards
digocampeao has shuffled deck.
digocampeao drew 6 cards
Put Hoppip onto bench
Put Hoppip onto bench
Chaotic Swell is now in play.
Trumbeak (LOT 165) used Mountain Migration
Put [Trumbeak (LOT 165)] to Lost Zone
B put the checked card back on top of their opponent's deck.
Cottonee used Lost March
Cottonee did 60 damage to Tapu Lele-GX
Between turns
Turn 3 begins
digocampeao drew 1 card
digocampeao played Cherish Ball.
Put [Zoroark-GX (SMP SM84)] to Hand
digocampeao has shuffled deck.
Zorua evolved into Zoroark-GX
Attached a Double Colorless Energy (GRI 166) to Tapu Lele-GX.
Poison Barb (SUM 124) is attached to Tapu Lele-GX
digocampeao played Nest Ball.
Put Zorua onto bench.
digocampeao has shuffled deck.
Tapu Lele-GX used Energy Drive
Tapu Lele-GX did 80 damage to Cottonee
Cottonee was knocked out
Double Colorless Energy (GRI 166) was discarded
digocampeao took one prize card.
Emolga is now active
Between turns
Turn 4 begins
QuazaTCG drew 1 card
Emolga has used Nuzzly Gathering
Put [Emolga (TEU 46)] to Hand
QuazaTCG has shuffled deck.
Hoppip evolved into Skiploom
Skiploom has used Floral Path to the Sky
Put [Skiploom (LOT 13), Hoppip (LOT 12)] to Lost Zone
QuazaTCG has shuffled deck.
QuazaTCG played Lost Blender.
Put [Twin Energy (RCL 209), Emolga (TEU 46)] to Lost Zone
QuazaTCG drew 1 card
Put Mew onto bench
Emolga retreated.
Hoppip is now active
Between turns
Turn 5 begins
digocampeao drew 1 card
digocampeao played Nest Ball.
Put Rattata onto bench.
digocampeao has shuffled deck.
Zoroark-GX has used Trade
Nihilego-GX (CIN 114) was discarded
digocampeao drew 2 cards
digocampeao played Cherish Ball.
Put [Zoroark-GX (SMP SM84)] to Hand
digocampeao has shuffled deck.
Ditto Prism Star has used Almighty Evolution
Ditto Prism Star evolved into Zoroark-GX
Attached a Double Colorless Energy (GRI 166) to Zoroark-GX.
digocampeao played Acerola.
Scooped up [Tapu Lele-GX (SMA SV94), Double Colorless Energy (GRI 166), Poison Barb (SUM 124)]
Put [Double Colorless Energy (GRI 166), Poison Barb (SUM 124)] to Hand
Zoroark-GX is now active
Zoroark-GX used Riotous Beating
Zoroark-GX did 80 damage to Hoppip
Hoppip was knocked out
digocampeao took one prize card.
Mew is now active
Between turns
Turn 6 begins
QuazaTCG drew 1 card
Emolga has used Nuzzly Gathering
Put [Emolga (TEU 46)] to Hand
QuazaTCG has shuffled deck.
Between turns
Turn 7 begins
digocampeao drew 1 card
Rattata evolved into Raticate
Tapu Lele-GX has used Wonder Tag
Put [Guzma (SMA SV84)] to Hand
digocampeao has shuffled deck.
Put Tapu Lele-GX onto bench
digocampeao played Guzma.
Jumpluff is now active
Raticate is now active
Raticate retreated.
Zoroark-GX is now active
Zoroark-GX used Riotous Beating
Zoroark-GX did 100 damage to Jumpluff
Jumpluff was knocked out
digocampeao took one prize card.
Emolga is now active
Between turns
Turn 8 begins
QuazaTCG drew 1 card
Attached a Double Colorless Energy (GRI 166) to Mew.
Emolga retreated.
Mew is now active
[QuazaTCG]: hmmm won't let me lost march
TURN TIMER: a Timeout Allowance was consumed to add 60 seconds to turn time
[QuazaTCG]: cottonee is in discard as well, so It should work
Emolga has used Nuzzly Gathering
QuazaTCG has shuffled deck.
Mew used Encounter
Put [Jirachi-EX (PLB 98)] to Hand
QuazaTCG has shuffled deck.
Between turns
Turn 9 begins
digocampeao drew 1 card
Zoroark-GX used Riotous Beating
Zoroark-GX did 100 damage to Mew
Mew was knocked out
Double Colorless Energy (GRI 166) was discarded
digocampeao took one prize card.
Emolga is now active
Between turns
Turn 10 begins
QuazaTCG drew 1 card
AllProRush is now a spectator of the game from neutral POV

I think mew is only if the Pokémon is in play on your side of the field you are probably mixing up mew with marshadow GX as that allows you to use the moves of Pokémon that are in your discard that are also basics