RsyncOSX: Crash and close in 6.4.6.

If I open 6.4.6, and mouse-click on the SSH tab, program immediately terminates. Crash included below.

Do you need more info?

Process:               RsyncOSX [51797]
Path:                  /Applications/RsyncOSX.app/Contents/MacOS/RsyncOSX
Identifier:            no.blogspot.RsyncOSX
Version:               6.4.6 (1)
Code Type:             X86-64 (Native)
Parent Process:        ??? [1]
Responsible:           RsyncOSX [51797]
User ID:               507

Date/Time:             2020-09-24 17:18:15.732 +0200
OS Version:            Mac OS X 10.15.6 (19G2021)
Report Version:        12
Bridge OS Version:     4.6 (17P6610)
Anonymous UUID:        0AA7CFD5-28BA-AE3B-7C6E-ABE05BB5F055

Sleep/Wake UUID:       09D9AF68-6484-4BA1-9554-130C8BE6DCFB

Time Awake Since Boot: 360000 seconds
Time Since Wake:       100000 seconds

System Integrity Protection: enabled

Crashed Thread:        0  Dispatch queue: com.apple.main-thread

Exception Type:        EXC_BAD_INSTRUCTION (SIGILL)
Exception Codes:       0x0000000000000001, 0x0000000000000000
Exception Note:        EXC_CORPSE_NOTIFY

Termination Signal:    Illegal instruction: 4
Termination Reason:    Namespace SIGNAL, Code 0x4
Terminating Process:   exc handler [51797]

Application Specific Information:
Performing @selector(_changeSelectedSegment:) from sender NSSegmentedControl 0x7fb70c0217a0

The crash is largely similar in properties if I press the button with the keyboard, instead of the mouse:

Process:               RsyncOSX [51876]
Path:                  /Applications/RsyncOSX.app/Contents/MacOS/RsyncOSX
Identifier:            no.blogspot.RsyncOSX
Version:               6.4.6 (1)
Code Type:             X86-64 (Native)
Parent Process:        ??? [1]
Responsible:           RsyncOSX [51876]
User ID:               507

Date/Time:             2020-09-24 17:25:25.743 +0200
OS Version:            Mac OS X 10.15.6 (19G2021)
Report Version:        12
Bridge OS Version:     4.6 (17P6610)
Anonymous UUID:        0AA7CFD5-28BA-AE3B-7C6E-ABE05BB5F055

Sleep/Wake UUID:       09D9AF68-6484-4BA1-9554-130C8BE6DCFB

Time Awake Since Boot: 360000 seconds
Time Since Wake:       100000 seconds

System Integrity Protection: enabled

Crashed Thread:        0  Dispatch queue: com.apple.main-thread

Exception Type:        EXC_BAD_INSTRUCTION (SIGILL)
Exception Codes:       0x0000000000000001, 0x0000000000000000
Exception Note:        EXC_CORPSE_NOTIFY

Termination Signal:    Illegal instruction: 4
Termination Reason:    Namespace SIGNAL, Code 0x4
Terminating Process:   exc handler [51876]

Application Specific Information:
Performing @selector(_changeSelectedSegment:) from sender NSSegmentedControl 0x7fb0e500f5e0

If I go to preferences, and check "use rsync 3.1.x" etc, and when I press "save" the program closes, but no crash window appears. Same for when I uncheck. 

Is this expected behaviour?