I think also they do not know very well how to use Phoenix. And I will explain here a quick guide how it should be used.

Phoenix is opening a channel slightly bigger than what are you depositing, I could say with a 10% more. And for each channel opening is charging a 3000 fee. If you start spending from that channel, DO NOT spend it all, because they will close it. If you leave some sats in the channel and make another deposit from another LN wallet, but no more than the size of the channel (I would say with a 5% less), the sats will fit into that already open channel and will not be opening a new one. So no more 3000 sats fee.

If you deposit from an onchain address, then it will open a new channel even if you already have an almost empty channel.

I suggest to make first time a bigger deposit, and like that opening a bigger channel. Spend from that channel slowly until you reach the balance of 1% of it. Then refill. until 99%. And so on. In that way you keep that channel open and pay less fees.

Also keep in mind that after you open a bigger channel and do not want to open more channels, by mistake, disable the option “automatic on-the-fly channel creation” from Settings - Payment options and fees. Activate that option only when you want to open new channels. Remember, if you do not have enough “space” to receive, the payment will be failed, with that option disabled.

If you still have let's say 3 channels of 1M sats each with a 500k sats balance, you could still receive a 900k sats payment split into those 3 channels. But is not always working, it depends on the liquidity and routes in that moment that ACINQ have them.

TLDR: is better to not use small channels on Phoenix and try to never empty them totally, so to reuse.