The clock panel applet does not work as expected in the newest versions of LXDE. If the clock is set to not show seconds in the display when waking from suspend the clock will not update until the time actually changes in the applet which means it can take up to a minute for the clock to update when seconds are not shown. The work around to this is to display seconds on the clock which allows it to update after suspend within one second. Sadly the clock does not display seconds correctly as it skips them by one to three at least once a minute, often more.
This is also not the first time there have been problems with the panel clock which clearly illustrates this to be an ongoing problem for the developers.

Lubuntu has not always had LTS support. Luckily they do offer a 3-year LTS now but it is shorter than other Ubuntu spins that receive a full 5 years of support.

Being a modern desktop many users expect compositing, even on lightweight systems. Without compositing, there will be screen tearing, a lot of it. Though there is built in support for users to add their own compositors such as Compton.