2 days ago i bought 87€ worth of BTC from Safello with a fee of 6€, nothing unusual and i received it within 15 minutes but the amount was down to 70€ when i finally had it in my wallet! does electrum have hidden fees? this have never happened to me before.
This has nothing to do with Electrum itself, the price of Bitcoin against EUR went down in the meantime which reduced the amount of EUR it's worth. You should still have the same amount of BTC you received, check that.
I sent the 70€ as i've done several times to the same adress as before but it just sat there for several hours with 0 confirmations so i canceled it yesterday afternoon, it's still on 0 confirmations and i have no idea what is going on.
Extremely high network fees in the past few days due to a shortage in mining hashrate and blocks is causing thousands of transactions to be stuck in the mempool for several days. Your best option is to wait it out for the mining farms to restore their full capacity, or to increase the fee to about 150 sats/byte (but read the rest of the post first)
Still have the amount in my wallet so i tried to send it to another wallet incase there is an issue with electrum i thought.. that transaction only have a yellow triangle with an "!" inside it, and its named unconfirmed parent.
When you cancelled the first transaction, it made a transaction that sends your money to another address in your wallet (a double-spend), which by the way is still unconfirmed, then your second "unconfirmed parent" transaction also became stuck because it's trying to spend bitcoin from the second address that hasn't been received yet. Thats a Child-Pays-For-Parent transaction.
2 weeks ago it worked flawlessly without issues as usual but.. what the hell is happening? Will i get another "unconfirmed parent" if i make another transaction?
Yes, in particular don't cancel the second transaction and try to send it to a third address or you will get a third unconfirmed parent and be expending fees for yet another transaction.
There is a way to purge these unconfirmed transactions from your Electrum client and create an entirely new transaction with no unconfirmed parent (so you can set higher fees), but it involves the console and I need to recall it from memory.