This is conspiracy based on a misinterpretation of the recent decision taken by the Latvian government. This message is consistent with recurring narratives about the West's attempts to disrupt Belarusian-Russia relations by any means and groundless Russophobic tendencies and measures taken by the Baltic states.
Taken that Lithuania considers the Belarusian NPP unsecure and intends to end energy imports from Belarus and that, until recently, the Lithuanian-Belarusian border had been serving the Baltic states as the only point of trade in energy with third countries, Latvia decided to open an energy trade point at the Latvian-Russian border.
On 13 August 2019, the Latvian electricity transmission system operator informed: "With the aim to timely mitigate the risks of shortened electricity flows or negative tariff fluctuations, today the Cabinet of Ministers approved the proposal by the Ministry of Economy to place the electricity trade at the Latvian border after Lithuania terminates trade in electricity with Belarus. This decision will ensure that the present-tie conditions on trade with third countries will remain in place." The message issued by the Latvian government gives an identical reason behind the decision.
After Lithuanian president Gitanas Nausėda voiced sadness over Latvia’s decision to purchase electrical energy produced at Astravets nuclear power plant in Belarus, Latvian Prime Minister Krišjānis Kariņš made a statement, saying that: "I can repeat that the Latvian government has not made the decision to buy electricity in Belarus.”
Previously pro-Kremlin outlets speculated about various Western measures aimed at disrupting Belarusian-Russina relations, including Poland's decision not to invite Putin to the WWII commemoration ceremony, and producing the popular Chernobyl series. See a collection of disinformation cases concerning the construction of the Belarusian NPP here.