Good morning, @Riaan Pretorius.

Do you have TC_QUIT_MODE and QUIT_MODE defined in your runtime configuration file?

"This variable lets you control how your COBOL application shuts down when no client activity occurs during the interval defined by TC_CHECK_ALIVE_INTERVAL. Setting TC_QUIT_MODE to -1 (the default value) shuts your program down according to the value chosen for the QUIT_MODE configuration variable."

Home
ACUCOBOL-GT extend V10.5.1
ACUCOBOL-GT Version 10.5.1 Documentation Set
Appendices
Appendix H. Configuration Variables
Configuration Variables
TC_QUIT_MODE
https://docs.rocketsoftware.com/bundle/acucobolgt_dg_1051_html/page/BKUSUSCONFS299.html

Regards.

We are using those settings in our configuration file

QUIT_MODE 0
TC_CHECK_ALIVE_INTERVAL 300
TC_QUIT_MODE -1

Thank you

With these settings, when you click on the [X] of the web browser, the remote runtime should receive the 0 value from QUIT_MODE and shut down.
(0 = "Always Close: the runtime halts the program whenever Close is selected from the system menu.")

What version of AcuToWeb are you working with?

Do you have other settings in the gateway configuration file that could impact this behaviour?

If the issue persists, I invite you to submit a new Case on the RCC portal - https://www.rocketsoftware.com/support

We'll continue the analysis there, with the help of client and server logs.