As per latest update, they have a system glitch daw.
Here is their official statement from their official Facebook page:

This has caused major concerns sa mga GCash users in terms of security. Because of this, I strongly believe na bumaba na ang confidence nila to store their funds and do transactions sa GCash.
I have checked mine recently and so far luckily as ease lang balance ko. Kaya I do not store much money sa kanila as well as Paymaya, banks, etc.
Much better sa hardware wallet na lang i store to be safe talaga ating hard earned money. Dito ko na store emergency funds ko eh just in case ma hack ako sa isang wallet, multiple wallets, etc. Ginawa ko lang naman ang GCash, Paymaya at banks as cashout source and not to save.