cgi error not seen before

from the error log:
[Fri Mar 06 *09:57:01.202192 2026*] [cgi:error] [pid 23494:tid 0000022C]
(70008)Partial results are valid but processing is
incomplete: [client 47.196.142.173:61821] ZSRV_MSG0818: Error reading
request entity data, referer: (url here)

the url was no different than others, and the user made the exact same
request 20 or so minutes later, with the same url values, with no issue.
There are many thousands of page requests daily, and never this message.

from the access log
[06/Mar/2026:09:57:01 -0500] "*POST* /xxxx/MZ1DOCUPL2.pgm HTTP/1.1" *400
223 *"https:...

V7R5 and near latest groups (within a month).

*I did notice the PGM-QZSRCGI did end (less than a second before error)
with a sev 0 just before the above error (as if the cgi ending one job and
starting another had an issue...)*
Display Spooled
File
File . . . . . : QPJOBLOG
Page/Line 3178/21
Control . . . . . -4
Columns 1 - 130
Find . . . . . .

*...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8....+....9....+....0....+....1....+....2....+....3

From user . . . . . . . . . :
QTMHHTP1
Thread . . . . : 00000020

Message . . . . : Object XSFWRSC in
QTEMP type *FILE deleted.
CPF1164 Completion 00 03/06/26 *09:57:01.302409 * QWTMCEOJ
QSYS 0161 *EXT *N
From user . . . . . . . . . :
QTMHHTP1
Thread . . . . : 00000020

Message . . . . : Job
105502/QTMHHTTP/XXXW ended on 03/06/26 at 09:57:01;
18.720 seconds used; end code 0 .


Jim Franz