Is there any bug or known issue on MX 14.53 regarding VPN ?
We had a couple of instances last month that Client VPN and site-to-site VPN got disconnected just randomly in the middle of the day. Checked with ISP as well, no issue from ISP.
14.53 is now a legacy release and the 14.x train isn't receiving updates. 15.44 is the current stable firmware so the first thing I'd do is upgrade to at least that so you can get support. If the devices are older models they will go to 14.55 that is still supported.
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