I was about to submit a bug, but found out yours : I have this same problem in a natural village in 20w17a.
I settled in this village when I first started a new game, and terraformed the paths so that villagers could get everywhere, torched the whole place to avoid monster spawn and over several days, everything went well, there are multiple farmers so they multiplied quickly.
I build a Fletching Table for the one living right next to where I settled my own home, and it succeeded : I got a Novice Fletcher who had the gems for sticks trade.
Leveled him up over several days until one time he wouldn't reset trades. I went to his workstation at work time, and it was occupied by a new villager ! So I build another Fletching Table for the original Fletcher and he took it, right next to the home where he sleeps.
All went well for several days, I leveled him to Master Fletcher and enjoyed the trades, until once again he wouldn't reset over several days ! I went to his new workstation at work time .... and yes it was yet again occupied by a new villager.
Curious, I waited night time, following my original Master Fletcher and I discovered he moved home and now lives at the far other side of the village ! So not only he got his workstation stolen twice, but now also his bed and had to move to another one.
During day time, I constructed another Fletching Table right under his nose, but this time he wouldn't take it, and it's yet another new villager who became my 4th Fletcher ....
I'm completely fed up with this, I hope it will be fixed for 1.16 release ! This is game breaking, you can't maintain a village like this.
Oliv
I was about to submit a bug, but found out yours : I have this same problem in a natural village in 20w17a.
I settled in this village when I first started a new game, and terraformed the paths so that villagers could get everywhere, torched the whole place to avoid monster spawn and over several days, everything went well, there are multiple farmers so they multiplied quickly.
I build a Fletching Table for the one living right next to where I settled my own home, and it succeeded : I got a Novice Fletcher who had the gems for sticks trade.
Leveled him up over several days until one time he wouldn't reset trades. I went to his workstation at work time, and it was occupied by a new villager ! So I build another Fletching Table for the original Fletcher and he took it, right next to the home where he sleeps.
All went well for several days, I leveled him to Master Fletcher and enjoyed the trades, until once again he wouldn't reset over several days ! I went to his new workstation at work time .... and yes it was yet again occupied by a new villager.
Curious, I waited night time, following my original Master Fletcher and I discovered he moved home and now lives at the far other side of the village ! So not only he got his workstation stolen twice, but now also his bed and had to move to another one.
During day time, I constructed another Fletching Table right under his nose, but this time he wouldn't take it, and it's yet another new villager who became my 4th Fletcher ....
I'm completely fed up with this, I hope it will be fixed for 1.16 release ! This is game breaking, you can't maintain a village like this.