The European Union insists that EDF must sell energy at very discounted prices, so that third-party "providers" can make an entry on the energy market. The idea was that they would eventually sell their own energy supply, but most just pocketed the difference between the dirt-cheap energy & what they charged customers, then ran away the moment there was any hint of change on the horizon.
Or, to put it in simpler, blunter terms: in the name of "competition", EDF was forced to heavily subsidize companies that turned out to be nothing more than rent-seekers that only sought to, effectively, grab free subsidy money.
Here are some articles about it:
2022: https://www.theguardian.com/business/2022/aug/10/edf-sues-fr... 2023: https://www.ft.com/content/e2fc3abf-4803-4561-8ef2-0c77fd2d0... 2024: https://www.bruegel.org/policy-brief/europes-under-radar-ind...