diff --git a/src/custom-sort/sorting-spec-processor.spec.ts b/src/custom-sort/sorting-spec-processor.spec.ts
index 03cc210..7632209 100644
--- a/src/custom-sort/sorting-spec-processor.spec.ts
+++ b/src/custom-sort/sorting-spec-processor.spec.ts
@@ -957,6 +957,24 @@ describe('SortingSpecProcessor error detection and reporting', () => {
 	})
 })
 
+const txtInputTargetFolderCCC: string = `
+target-folder: CCC
+`
+
+describe('SortingSpecProcessor advanced error detection', () => {
+	it('should retain state of duplicates detection in the instance', () => {
+		let processor: SortingSpecProcessor = new SortingSpecProcessor(errorsLogger);
+		errorsLogger.mockReset()
+		const inputTxtArr: Array<string> = txtInputTargetFolderCCC.split('\n')
+		const result1 = processor.parseSortSpecFromText(inputTxtArr, 'another-mock-folder', 'sortspec.md')
+		const result2 = processor.parseSortSpecFromText(inputTxtArr, 'mock-folder', 'custom-name-note.md')
+		expect(result1).not.toBeNull()
+		expect(result2).toBeNull()
+		expect(errorsLogger).toHaveBeenCalledTimes(1)
+		expect(errorsLogger).toHaveBeenCalledWith(`${ERR_PREFIX} 2:DuplicateSortSpecForSameFolder Duplicate sorting spec for folder CCC ${ERR_SUFFIX}`)
+	})
+})
+
 describe('convertPlainStringSortingGroupSpecToArraySpec', () => {
 	let processor: SortingSpecProcessor;
 	beforeEach(() => {
diff --git a/src/custom-sort/sorting-spec-processor.ts b/src/custom-sort/sorting-spec-processor.ts
index e435c68..be2aadf 100644
--- a/src/custom-sort/sorting-spec-processor.ts
+++ b/src/custom-sort/sorting-spec-processor.ts
@@ -359,6 +359,11 @@ export class SortingSpecProcessor {
 	problemAlreadyReportedForCurrentLine: boolean
 	recentErrorMessage: string
 
+	// Helper map to deal with rule priorities for the same path
+	//   and also detect non-wildcard duplicates.
+	//   The wildcard duplicates were detected prior to this point, no need to bother about them
+	pathMatchPriorityForPath: {[key: string]: WildcardPriority} = {}
+
 	// Logger parameter exposed to support unit testing of error cases as well as capturing error messages
 	//  for in-app presentation
 	constructor(private errorLogger?: typeof console.log) {
@@ -370,10 +375,17 @@ export class SortingSpecProcessor {
 						  sortingSpecFileName: string,
 						  collection?: SortSpecsCollection
 	): SortSpecsCollection {
+		// reset / init processing state after potential previous invocation
 		this.ctx = {
 			folderPath: folderPath,   // location of the sorting spec file
 			specs: []
 		};
+		this.currentEntryLine = null
+		this.currentEntryLineIdx = null
+		this.currentSortingSpecContainerFilePath = null
+		this.problemAlreadyReportedForCurrentLine = null
+		this.recentErrorMessage = null
+
 		let success: boolean = false;
 		let lineIdx: number = 0;
 		for (let entryLine of text) {
@@ -439,11 +451,6 @@ export class SortingSpecProcessor {
 					collection.sortSpecByWildcard = sortspecByWildcard
 				}
 
-				// Helper transient map to deal with rule priorities for the same path
-				//   and also detect non-wildcard duplicates.
-				//   The wildcard duplicates were detected prior to this point, no need to bother about them
-				const pathMatchPriorityForPath: {[key: string]: WildcardPriority} = {}
-
 				for (let spec of this.ctx.specs) {
 					for (let idx = 0; idx < spec.targetFoldersPaths.length; idx++) {
 						const originalPath = spec.targetFoldersPaths[idx]
@@ -452,7 +459,7 @@ export class SortingSpecProcessor {
 						let path: string
 						[path, detectedWildcardPriority] = stripWildcardPatternSuffix(originalPath)
 						let storeTheSpec: boolean = true
-						const preexistingSortSpecPriority: WildcardPriority = pathMatchPriorityForPath[path]
+						const preexistingSortSpecPriority: WildcardPriority = this.pathMatchPriorityForPath[path]
 						if (preexistingSortSpecPriority) {
 							if (preexistingSortSpecPriority === WildcardPriority.NO_WILDCARD && detectedWildcardPriority === WildcardPriority.NO_WILDCARD) {
 								this.problem(ProblemCode.DuplicateSortSpecForSameFolder, `Duplicate sorting spec for folder ${path}`)
@@ -464,7 +471,7 @@ export class SortingSpecProcessor {
 						}
 						if (storeTheSpec) {
 							collection.sortSpecByPath[path] = spec
-							pathMatchPriorityForPath[path] = detectedWildcardPriority
+							this.pathMatchPriorityForPath[path] = detectedWildcardPriority
 						}
 					}
 				}
diff --git a/src/main.ts b/src/main.ts
index 4cf6878..307f439 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -55,6 +55,8 @@ export default class CustomSortPlugin extends Plugin {
 		let errorMessage: string
 		// reset cache
 		this.sortSpecCache = null
+		const processor: SortingSpecProcessor = new SortingSpecProcessor()
+
 		Vault.recurseChildren(this.app.vault.getRoot(), (file: TAbstractFile) => {
 			if (failed) return
 			if (file instanceof TFile) {
@@ -68,7 +70,6 @@ export default class CustomSortPlugin extends Plugin {
 					const sortingSpecTxt: string = mCache.getCache(aFile.path)?.frontmatter?.[SORTINGSPEC_YAML_KEY]
 					if (sortingSpecTxt) {
 						anySortingSpecFound = true
-						const processor: SortingSpecProcessor = new SortingSpecProcessor()
 						this.sortSpecCache = processor.parseSortSpecFromText(
 							sortingSpecTxt.split('\n'),
 							parent.path,