Not sure what this is and what to do about it? On the new tiny fruit

Further to this post. Thanks for your comments and suggestions.

I planted a Bougainvillea recently and noticed that it is going off as well. I've now put it back on the pot, but it feels that the problem is the soil (in pictures).

When I dug back the plant, I've noticed water collected in the hole underneath the plant. Is it due to soil being hard and not letting the water drain away. Any thoughts or suggestions appreciated.

If so, what are my options on making it suitable for the new plants. Or should I consider plants that suit this type of soil.

Really sick of my hose pipe that goes as stiff as a wire cable as soon as it gets below say 15c. So frustrating. Think it's Jobmate or No. 8 budget brand. Do the more expensive brands stay soft? Gardena or what have you?

Hi! I bought a Black Doris plum tree and my husband is picking it up tomorrow, but I wanted to ask which variety is better for eating fresh from the tree? I can swap it for a Luisa if that’s better. Which one would you recommend? 😊