3226075 - SAP GUI Web-based transaction sessions are suddenly closing when IE-mode is active in Microsoft Edge browser

After installation of SAP GUI 770, web-based transaction sessions suddenly and randomly close when IE-mode is active in Microsoft Edge browser. The issue can be characterized by the following scenario:

• It can occur randomly, around 4x a day for some users
• Most part of the time it can't be reproduced, the GUI sessions close at different actions and times, sometime only when a transaction code is inserted
• The following error message we can be seeing in SM21 and dev_ logs:

Dev_W:

M ThSoftCancel: delete XXXX_XXXXX_XX because of soft cancel with reason DP_SOFTCANCEL_SAP_GUI_DISCONNECT
M ThPerformDeleteThisSession: switch off statistics
M *** WARNING => ThResFreeSession: free resources of XXXX_XXXXX_XX (normal mode, complete free), rc=WARNING-SESSION-SOFT_CANCEL, db_action=TH_DB_ROLLBACK [thxxmode.c 890]
M ***LOG R47=> ThResFreeSession, delete () [thxxmode.c 1166]
M ThResFreeSession: delete XXXX_XXXXX_XX

Dev_disp:

***LOG Q0I=> NiIRead: P=XX.X.XX.XXX:XXXXX; L=XX.X.XX.XX:XXXX: recv (10054: WSAECONNRESET: Connection reset by peer) [D:/depot/bas/753_REL/src/base/ni/nixxi.cpp XXXX]
*** ERROR => NiIRead: SiRecv failed for hdl XXX/sock XXXX
(SI_ECONN_BROKEN/10054; I4; ST; P=XX.X.XX.XXX:XXXXX; L=XX.X.XX.XX:XXXX) [nixxi.cpp XXXX]
***LOG Q04=> DpRTmPrepareReq, NiBufReceive (XXXX XXXXXXXX XXX DELT00XXX) [dpTerminal.c XXX]
|GUI |XXXX_XXXXX |400|XXXXXXXX |XXXXXXXXX  |hh:mm:ss|43 |SAPLSMTR_NAVIGATION |high| | |SESSION_MA|
DpRTmPrepareReq: network error of client XXXX_XXXXX in state DP_LOGGED_IN: NiBufReceive (-6: NIECONN_BROKEN)
NiHLGetHostName: got address XX.X.XX.XXX from operating system
NiIGetHostName: addr XX.X.XX.XXX = hostname '<hostname>'
DpRTmPrepareReq: client address of XXXX_XXXXX is XX.X.XX.XXX (<hostname>)
DpHdlSoftCancel: cancel request for XXXX_XXXXX _XX received from DISP (reason=DP_SOFTCANCEL_SAP_GUI_DISCONNECT)
DpHdlSoftCancel: cancel request for XXXX_XXXXX _XX received from DISP (reason=DP_SOFTCANCEL_SAP_GUI_DISCONNECT)

• SAP GUI for Windows
• Microsoft Edge Browser 

IE-mode, SAP GUI, Web-based transaction, Microsoft Edge, WSAECONNRESET, DP_SOFTCANCEL_SAP_GUI_DISCONNECT, Connection reset by peer. , KBA , BC-NET , Obsolete - Formerly used for network tests , BC-FES-CTL , SAP GUI for Windows Controls , Problem