Amazon’s plan to curb its aggressive logistics network expansion following a $3.8 billion first-quarter net loss has sent tremors of unease through some Connecticut communities where the e-commerce giant was eyeing new distribution facilities — a potential source of significant new jobs and tax revenues. The Plainfield project is being led by Exeter Property Group, a Pennsylvania-based real estate investment and development firm. Amazon and Exeter did not respond to requests for comment. In Waterbury, officials said they have received assurances from a development group proposing a massive Amazon regional distribution center in the city, but that a smaller last-mile fulfillment center is “on hold.” In an April 28 earnings call with investors, Amazon Chief Financial Officer Brian Olsavsky blamed several factors for the company’s multibillion-dollar loss. Higher gas prices and the war in Ukraine were factors outside the company’s control, but he also blamed overdevelopment of labor and facilities.