Tag groups on /t page are not displayed in alphabetical order

[HAZET-WERK]

Summary

On the Tags page (/t), the tag groups in the left navigation are not displayed in alphabetical order.

The tags within each group appear to be sorted correctly, but the letter groups themselves are not.

Environment

• Wiki.js: 2.x (latest available at the time of writing)
• Browser: Google Chrome
• OS: macOS (also reproducible on Windows)

Steps to reproduce

1. Open the Tags page (/t).
2. Ensure that tags exist for multiple starting letters (A, B, C, D, E, F, G, ...).
3. Observe the left sidebar.

Actual behavior

The letter groups are displayed in a non-alphabetical order.

Example:

A
B
C
D
E
S
V
F
G
H
I
O
J
K
Z
M
N
P
Q
R
T
W
Ü

The tags inside each individual letter group appear to be correct.

Expected behavior

The letter groups should always be displayed alphabetically, for example:

A
B
C
D
E
F
G
H
I
J
K
M
N
O
P
Q
R
S
T
Ü
V
W
Z

(or according to the locale-specific collation rules used by Wiki.js).

Notes

The issue only affects the order of the letter groups in the sidebar.

The individual tags within each group appear to be ordered correctly.

The generated DOM already contains the incorrect group order, so this does not appear to be a browser rendering issue.

I could not find an existing bug report describing this behaviour.

If required, I can also provide the generated HTML/DOM from the affected page.