EM7455 SMS Express scrambles messages

SMS Express scrambles text messages upon receiving them when text messages are sent by service providers, in other words, not physically sent from a mobile phone. All other features work correctly. What could be the reason? Is there any way to do diagnostics in order to determine what is going on?

Here you can see an example of two scrambled messages:

Can anyone tell me if SMS Express stores text messages within the SIM card? If not, where are they stored?

I am not familiar with AT commands, but it looks like no text messages are stored in the SIM card:
AT+CPMS?
+CPMS: “SM”,0,20,“SM”,0,20,“SM”,0,20

I was able to catch text message that becomes unreadable (text messages in this particular case are shown as empty, From number is truncated (no last digit), Received field shows only time and no date (full date is always shown for other messages) when I try to open it with SMS Express.

Here it is how it looks like in SMS Express:

And here is my terminal output (notice that phone number is incorrectly given in Text Mode):

AT+CMGF=1

OK

AT+CMGL="ALL"

+CMGL: 0,"REC READ","49514849",,"17/06/19,22:43:32+12"
004E006500740065006900730069006E0067006100690020012F00760065007300740061007300200075017E006B006C006100750073006F00730020006B006F006400610073002E0020004E006F0072011700640061006D006100730020006700610075007400690020006B006F006400750073002C0020006E0075006D0065007200690075
+CMGL: 1,"REC READ","49514849",,"17/06/19,22:43:32+12"
0020003100330030003100200073006901730073006B00200053004D00530020012F00720061016101190073003A0020003F



AT+CMGF=0

OK
AT+CMGL=4

+CMGL: 0,1,,157
07917360899919F54007D0B1192C060008716091223423218C050003900201004E006500740065006900730069006E0067006100690020012F00760065007300740061007300200075017E006B006C006100750073006F00730020006B006F006400610073002E0020004E006F0072011700640061006D006100730020006700610075007400690020006B006F006400750073002C0020006E0075006D0065007200690075
+CMGL: 1,1,,73
07917360899919F54407D0B1192C06000871609122342321380500039002020020003100330030003100200073006901730073006B00200053004D00530020012F00720061016101190073003A0020003F

I can confirm that when I use 3rd party program instead of SMS Express I receive messages correctly. Could anyone please give me any clues what is going on here?

Another symptom. Skylight has crashed upon receiving a text message. I have tried starting it again multiple times, but it always crashes instantly. So, I can no longer even open SMS Express, while 3rd party app is still able to read that last received message correctly. Is there any chance this software bug will be fixed by Sierra Wireless?

My terminal output with the last text message:

AT+CMGF=1

OK
AT+CMGL="ALL"

+CMGL: 0,"REC READ","49514849",,"17/06/19,22:43:32+12"
004E006500740065006900730069006E0067006100690020012F00760065007300740061007300200075017E006B006C006100750073006F00730020006B006F006400610073002E0020004E006F0072011700640061006D006100730020006700610075007400690020006B006F006400750073002C0020006E0075006D0065007200690075
+CMGL: 1,"REC READ","49514849",,"17/06/19,22:43:32+12"
0020003100330030003100200073006901730073006B00200053004D00530020012F00720061016101190073003A0020003F
+CMGL: 2,"REC READ","83758984696772",,"17/06/22,14:20:11+12"
537665696B692C557A73616B796D6173202336383338373720706172756F737461732E205072656B65732061747369696D74692067616C697465204A756D73207061746F676975206D65747520492D562031302D3139682C2056492030362E323464206E656469726273696D652C20536176616E6F7269752070722E203233372C204B61756E61732E416369752C206B6164206E6175646F6A
+CMGL: 3,"REC READ","83758984696772",,"17/06/22,14:20:11+12"
61746573206D757375207061736C6175676F6D69732E

OK
AT+CMGF=0

OK
AT+CMGL=4

+CMGL: 0,1,,157
07917360899919F54007D0B1192C060008716091223423218C050003900201004E006500740065006900730069006E0067006100690020012F00760065007300740061007300200075017E006B006C006100750073006F00730020006B006F006400610073002E0020004E006F0072011700640061006D006100730020006700610075007400690020006B006F006400750073002C0020006E0075006D0065007200690075
+CMGL: 1,1,,73
07917360899919F54407D0B1192C06000871609122342321380500039002020020003100330030003100200073006901730073006B00200053004D00530020012F00720061016101190073003A0020003F
+CMGL: 2,1,,160
07917360899919F5400DD0D365965A1C2201000071602241021121A0050003B60201A6F6727A9D6655F5F3F03ADF0ECF41231B6E86BBDD40F0B0BCFE9ED3C37317082A2FAFCB7350983E4FA7DBF434E81C66A7E96590B2DE9E83E061FAFB9CAE83DA657A1D946C594131582B9643B340D624086673C9686490BB4C4ECBC5F374BBCC024DC3F6B0FB2D4FD74170B90B249BDD58A065B8EE0ECF5DC171BACE02ADC364903B5C27BFD5
+CMGL: 3,1,,46
07917360899919F5440DD0D365965A1C22010000716022410211211D050003B60202C2F4F21CD4AECFEB207878CE0ED7CFEF767AEE02

OK