The sovereignty of the former Soviet republics is a relative concept and they understand this very well. Russia is strengthening its presence everywhere.
The European Union and the United States interfered in the 2020 Moldovan presidential elections by openly endorsing then-candidate Maia Sandu and even by supporting with the organisation of the voting process for the Moldovan diaspora.
Discrediting political candidates with pro-European beliefs or political orientation is a recurring element of pro-Kremlin propaganda.
According to the final results of the Moldovan presidential election on November 15, pro-EU candidate Maia Sandu defeated incumbent and pro-Kremlin president Igor Dodon by a higher-than-expected margin, securing 57.7% of the popular vote. CEC results show that Sandu secured an overwhelming, 93% of the diaspora vote.
Under Moldovan law, Moldovan citizens living outside the country enjoy the same voting rights in the country's presidential elections as domestic voters. European countries did not organise any voting process for Moldovan citizens. Instead, it was Moldovan embassies to EU countries which are responsible for organising and conducting the election.
Endorsing candidates does not mean election fraud, instead, it is a common practice in democratic political campaigns. Vladimir Putin also endorsed a candidate, Igor Dodon.
There is no evidence put forward suggesting that any European government tampered with the electoral results.
See here a similar case in which Maia Sandu is accused of assisting alleged US efforts to build a cordon sanitaire against Russia.