Soundtouch 20 preset pushing fails

[JeyP91]

SixBack firmware version

0.8.6

ESP32 hardware variant

ESP32-C3

Bose speaker(s) involved

SoundTouch 20, FW 27.0.6.46330.50

What happened?

I am trying to push presets to my Soundtouch 20. Unfortunately the process fails and no preset is saved.
The UI goes through the 4 steps and reports the first three steps as successful.

The check at the end fails:
✗ verify hardware /presets reflects the change
hardware did not save after retries (Bose-side issue or name-normalization).

In the logs I can see this:
[19:40:20][bg:push-preset] 192.168.1.117 slot 1 ABORT — /select=500 (no long-press attempted)

This is logged directly when clicking on "push to slot 1".

What did you expect to happen?

Pushing preset works as expected.

Steps to reproduce

1. Open WebUI
2. Drag Station to Slot 1
3. Click "Push to Slot 1"
4. Wait for process to finish

Logs / screenshots / diagnostic snapshot

...
[19:33:32][bg:push-preset] 192.168.1.117 slot 1 ABORT — /select=500 (no long-press attempted)
[19:33:35][700033][E][Preferences.cpp:47] begin(): nvs_open failed: NOT_FOUND
[19:33:45][710012][E][Preferences.cpp:47] begin(): nvs_open failed: NOT_FOUND
[19:33:56][heartbeat] up=720s  RSSI=-63  free-heap=90308  PSRAM-free=0
[19:33:56][720987][E][Preferences.cpp:47] begin(): nvs_open failed: NOT_FOUND
[19:34:03][727609][E][Preferences.cpp:47] begin(): nvs_open failed: NOT_FOUND
[19:34:06][731260][E][Preferences.cpp:47] begin(): nvs_open failed: NOT_FOUND
[19:34:17][741752][E][Preferences.cpp:47] begin(): nvs_open failed: NOT_FOUND
[19:34:26][heartbeat] up=750s  RSSI=-64  free-heap=90344  PSRAM-free=0
[19:34:26][bg:push-preset] 192.168.1.117 slot 1 ABORT — /select=500 (no long-press attempted)
[19:34:27][751645][E][Preferences.cpp:47] begin(): nvs_open failed: NOT_FOUND
[19:34:27][marge-ka] no eligible speakers
[19:34:37][761840][E][Preferences.cpp:47] begin(): nvs_open failed: NOT_FOUND
[19:34:47][771755][E][Preferences.cpp:47] begin(): nvs_open failed: NOT_FOUND
[19:34:56][heartbeat] up=780s  RSSI=-64  free-heap=89824  PSRAM-free=0
[19:34:57][781971][E][Preferences.cpp:47] begin(): nvs_open failed: NOT_FOUND
...