I have Verizon Messages+ on my phone, table, and desktop. I also use the web app version on occasion.
In the past, I have noticed a delay in sync between devices when my actual phone is turned off or in airplane mode. Mostly, I notice a string of messages come rolling in when I turn the phone back on. I never really tested this effect.
Now, on an international trip where I cannot use my phone as a cell phone (no sim), I thought I would use the Messages+ over wifi.
No messages are coming through.
Outgoing messages appear to sync. I can see the message I just went from the web show up in my tablet app.
No incoming messages appear. I even tried the #####@vtext.com option to send myself a text via email, but it did not come through. I tried an SMS from my Skype account and that did not arrive. I tried a text from my international phone and that did not arrive.
So, I'm curious. Does the physical phone associated with the account have to be on and connected to the cellular network for incoming messages to appear on all devices?
There is a more current discussion of Message+ use with a PC and a phone powered off (not on the network): https://community.verizonwireless.com/t5/Verizon-Messages/Does-integrated-messaging-work-if-my-phone...
The more current discussion is talking about SENDING text messages from the PC when the phone is off, not receiving them. I just tested from my iPad sending messages from my gmail account to my firstname.lastname@example.org and they came thru fine to my PC's Message+ webapp https://web.vma.vzw.com/vma/web2/Message.do when the phone was powered off. When using the downloaded Message+ desktop app v220.127.116.11, it also synchronized/received the messages sent from my iPad when the phone was powered off.
Are you signing in to the PC app using the phone's number/profile login? There might be something else going on for you.
I do have a second device (my iPad) logged into Message+ using my phone's number. Not sure if that is coming into play.
Turned off BOTH my phone and iPad so no other devices logged into Message+ using my phone number and STILL receiving text messages on the desktop Message+ app. Working fine for me and my Droid Turbo 2 phone's Message+ messaging in/out synchronizing on my Win10 desktop PC Message+ app when phone is OFF.
I know I rely on my messages Jav6 and you should be able to still receive your messages on the PC while your phone is off. I would love to help figure this out. I see that this has been going on for a while now. I know you have several devices active with Verizon Messages +. Does the same thing happen if you use your tablet? How long is it before you receive your message?