That’s no good. The recovery script is quite a brute force approach.
At this stage I’m thinking you may need to look at using an external programmer to check things? It could be your XIAO’s flashing device (on board SAMD21) is not working properly. Apart from that, the XIAO may actually be toast?
You’d need to use with the expansion board (for example) or solder wires on to the underside. You’ll also need a SWD programmer.
Let me know if you want more help going this route.