functions keys F1-F4 do not work with xterm

when using xterm, function keys 1-4 map to pqrs instead of 1234.
xrdb shows the right mapping:

<Key>F1:        string(0x1b) string("[11~")              \n\

        <Key>F2:        string(0x1b) string("[12~")              \n\

        <Key>F3:        string(0x1b) string("[13~")              \n\

        <Key>F4:        string(0x1b) string("[14~")              \n\

but when using said function keys we get:
P
Q
R
S

This is on Solaris 11.3 and 11.4
xterm version is XTerm(320), XTerm(333)

infocmp xterm

#       Reconstructed via infocmp from file: /usr/share/lib/terminfo/x/xterm

xterm|vs100|xterm terminal emulator,

        am, km, mir, msgr, xenl,

        cols#80, it#8, lines#65,

        acsc=``aaffggjjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{||}}~~,

        bel=^G, blink=\E[5m, bold=\E[1m, clear=\E[H\E[2J,