After planting two fruit trees, which were allowed to have no separate spaces between them, I was unable to plant more after buying or earning them after the first two. It doesn’t seem to matter what season since even a tree in season can’t be placed currently. I haven’t gone out of my way to test it on a fresh file because I’d have to get the greenhouse all over again which took me quite some time but the issue has not resolved itself for multiple in game seasons.
The screen recording I have linked is from my pc with gamepass and in version 1-162 using a mouse and keyboard. I did see people online mention having to clear out their entire greenhouse or fix the issue but I have not gone far enough in the game to risk that much profit on a maybe solution.
https://drive.google.com/file/d/111YEYEttqVdlKEaIHcFOilgdHj_uFV5c/view?usp=drive_web