Are there any space probes\landers which regain communication after being lost?
Contact was lost with IMAGE on
December 18, 2005, 07:39 UTC and it was detected again by amateur satellite hunter Scott Tilley on
January 20, 2018. You can read more about it in that Wikipedia article and this answer and this answer
SOHO was nearly lost. Communications was severely impacted by a loss of attitude control and antenna pointing. It was touch-and-go for a while:
From Is this what station keeping maneuvers look like, or just glitches in data? (SOHO via Horizons) (you can read more about it there):
If you look closely at the "top" there's a little blip, and excursion toward the sun. I think this is the famous, frightening episode in June to November 1998 when SOHO was almost lost. There is a page of recovery docs or you can read about it in Aerospace America May 1999: Saving SOHO or the article by ESA's F.C. Vandenbussche SOHO’s Recovery – An Unprecedented Success Story or for the more of the technical details, Roberts 2002 The SOHO Mission L1 Halo Orbit Recovery
From the Attitude Control Anomalies of 1998.
In this case the spacecraft was not lost so much as people simply stopped talking to it/looking for it for a while:
From Wikipedia's International Cometary Explorer
ISEE-3 was the first spacecraft to be placed in a halo orbit at the L1 Earth-Sun Lagrangian point. Renamed ICE, it became the first spacecraft to visit a comet, passing through the plasma tail of comet Giacobini-Zinner within about 7,800 km (4,800 mi) of the nucleus on September 11, 1985.
NASA suspended routine contact with ISEE-3 in 1997, and made brief status checks in 1999 and 2008.
On May 29, 2014, two-way communication with the spacecraft was reestablished by the ISEE-3 Reboot Project, an unofficial group with support from the Skycorp company. On July 2, 2014, they fired the thrusters for the first time since 1987. However, later firings of the thrusters failed, apparently due to a lack of nitrogen pressurant in the fuel tanks. The project team initiated an alternative plan to use the spacecraft to "collect scientific data and send it back to Earth", but on September 16, 2014, contact with the probe was lost.
The question Which Voyager spacecraft “mutinied”, and what really happened? describes a situation where the spacecraft was not really "lost" but it at least appeared that Voyager 2 was no longer taking commands.