GL7500: AT+WMANTSEL=11 + AT&W0 = firmware corruption

I’m trying to configure the GL7500 to only use the primary antenna since we don’t have anything connected to the diversity antenna port. The manual says the setting is stored with the AT&W command, but if I issue that command after changing the setting, the modem seems to become corrupted and must be left powered for several minutes (firmware recovery?) before it becomes responsive again. This doesn’t seem like the expected behavior…

[36] 1572999297.127441 LOG_String: MDM:AT
[36] 1572999297.157226 LOG_String: MDM:OK
[36] 1572999298.087829 LOG_String: MDM:AT+WMANTSEL?
[36] 1572999298.107330 LOG_String: MDM:+WMANTSEL: 00 OK
[36] 1572999298.127655 LOG_String: MDM:AT+COPS?
[36] 1572999298.277343 LOG_String: MDM:+COPS: 0,0,“Rogers Wireless”,7 OK
[36] 1572999298.297729 LOG_String: MDM:AT+COPS=2
[36] 1572999298.707336 LOG_String: MDM:OK
[36] 1572999313.878845 LOG_String: MDM:AT+WMANTSEL=11
[36] 1572999313.908264 LOG_String: MDM:OK
[36] 1572999313.928802 LOG_String: MDM:AT+WMANTSEL?
[36] 1572999313.948272 LOG_String: MDM:+WMANTSEL: 11 OK
[36] 1572999313.968505 LOG_String: MDM:AT&W0
[36] 1572999313.988250 LOG_String: MDM:OK
[36] 1572999314.008605 LOG_String: MDM:AT+FMR
[36] 1572999314.028320 LOG_String: MDM:GL7500.A.2.15.151600.201809201422.x7160_3 OK
[36] 1572999314.048583 LOG_String: MDM:AT+WMSN
[36] 1572999314.068328 LOG_String: MDM:Serial Number TY813185630310 OK
[36] 1572999314.538726 LOG_String: MDM:AT+CFUN=0

[38] 1572999580.043701 LOG_String: MDM:Enable
[38] 1572999584.112579 LOG_String: MDM:AT
[38] 1572999586.272247 LOG_String: MDM:AT
[38] 1572999588.432342 LOG_String: MDM:AT
[38] 1572999590.592468 LOG_String: MDM:AT
[38] 1572999592.752593 LOG_String: MDM:AT
[38] 1572999594.912780 LOG_String: MDM:AT