diff --git a/mission/tmtc/PersistentTmStore.cpp b/mission/tmtc/PersistentTmStore.cpp
index db953c4b..f4ce65ef 100644
--- a/mission/tmtc/PersistentTmStore.cpp
+++ b/mission/tmtc/PersistentTmStore.cpp
@@ -40,12 +40,12 @@ ReturnValue_t PersistentTmStore::buildDumpSet(uint32_t fromUnixSeconds, uint32_t
     if (not fileOrDir.is_regular_file(e)) {
       continue;
     }
+    sif::debug << "Path: " << fileOrDir.path() << std::endl;
     dumpParams.fileSize = std::filesystem::file_size(fileOrDir.path(), e);
     if (e) {
       sif::error << "PersistentTmStore: Could not retrieve file size: " << e.message() << std::endl;
       continue;
     }
-    // sif::debug << "Path: " << dumpParams.dirEntry.path() << std::endl;
 
     // File empty or can't even read CCSDS header.
     if (dumpParams.fileSize <= 6) {
@@ -83,7 +83,7 @@ ReturnValue_t PersistentTmStore::buildDumpSet(uint32_t fromUnixSeconds, uint32_t
   return returnvalue::OK;
 }
 
-uint8_t PersistentTmStore::extractSuffix(const std::string& pathStr) {
+std::optional<uint8_t> PersistentTmStore::extractSuffix(const std::string& pathStr) {
   std::string numberStr;
   // Find the position of the dot at the end of the file path
   size_t dotPos = pathStr.find_last_of('.');
@@ -91,11 +91,18 @@ uint8_t PersistentTmStore::extractSuffix(const std::string& pathStr) {
     // Extract the substring after the dot
     numberStr = pathStr.substr(dotPos + 1);
   }
-  int number = std::stoi(numberStr);
-  if (number < 0 or number > std::numeric_limits<uint8_t>::max()) {
-    return 0;
+  std::optional<uint8_t> number;
+  try {
+    number = std::stoi(numberStr);
+    if (number < 0 or number > std::numeric_limits<uint8_t>::max()) {
+      return number;
+    }
+
+  } catch (std::invalid_argument& exception) {
+    sif::error << "PersistentTmStore::extractSuffix: Exception " << exception.what()
+               << ", invald input string: " << numberStr << std::endl;
   }
-  return static_cast<uint8_t>(number);
+  return number;
 }
 
 ReturnValue_t PersistentTmStore::assignAndOrCreateMostRecentFile() {
@@ -195,6 +202,7 @@ ReturnValue_t PersistentTmStore::storePacket(PusTmReader& reader) {
     createMostRecentFile(suffix);
   }
 
+  sif::debug << "active file " << activeFile.value() << std::endl;
   // Rollover conditions were handled, write to file now
   std::ofstream of(activeFile.value(), std::ios::app | std::ios::binary);
   of.write(reinterpret_cast<const char*>(reader.getFullData()),
@@ -229,6 +237,8 @@ bool PersistentTmStore::updateBaseDir() {
   path preparedFullFilePath = basePath / baseName;
   basePathSize = preparedFullFilePath.string().length();
   std::memcpy(filePathBuf.data(), preparedFullFilePath.c_str(), basePathSize);
+  filePathBuf[basePathSize] = '_';
+  basePathSize += 1;
   baseDirUninitialized = false;
   return true;
 }
@@ -358,6 +368,7 @@ ReturnValue_t PersistentTmStore::createMostRecentFile(std::optional<uint8_t> suf
   size_t currentIdx;
   createFileName(currentTv, suffix, currentIdx);
   path newPath(std::string(reinterpret_cast<const char*>(filePathBuf.data()), currentIdx));
+  sif::debug << "creating new file: " << newPath << std::endl;
   std::ofstream of(newPath, std::ios::binary);
   activeFile = newPath;
   activeFileTv = currentTv;
@@ -383,8 +394,6 @@ void PersistentTmStore::getStartAndEndTimeCurrentOrLastDump(uint32_t& startTime,
 ReturnValue_t PersistentTmStore::createFileName(timeval& tv, std::optional<uint8_t> suffix,
                                                 size_t& fullPathLength) {
   unsigned currentIdx = basePathSize;
-  fileBuf[currentIdx] = '_';
-  currentIdx += 1;
   time_t epoch = tv.tv_sec;
   struct tm* time = gmtime(&epoch);
   size_t writtenBytes = strftime(reinterpret_cast<char*>(filePathBuf.data() + currentIdx),
diff --git a/mission/tmtc/PersistentTmStore.h b/mission/tmtc/PersistentTmStore.h
index e2ad3cd0..1694a8c9 100644
--- a/mission/tmtc/PersistentTmStore.h
+++ b/mission/tmtc/PersistentTmStore.h
@@ -40,7 +40,7 @@ struct PersistentTmStoreArgs {
 
 struct DumpIndex {
   uint32_t epoch;
-  uint8_t suffixIdx;
+  std::optional<uint8_t> suffixIdx;
   // Define a custom comparison function based on the epoch variable
   bool operator<(const DumpIndex& other) const { return epoch < other.epoch; }
 };
@@ -140,7 +140,7 @@ class PersistentTmStore : public TmStoreFrontendSimpleIF, public SystemObject {
   void fileToPackets(const std::filesystem::path& path, uint32_t unixStamp);
   ReturnValue_t loadNextDumpFile();
   ReturnValue_t createFileName(timeval& tv, std::optional<uint8_t> suffix, size_t& fullPathLength);
-  uint8_t extractSuffix(const std::string& pathStr);
+  std::optional<uint8_t> extractSuffix(const std::string& pathStr);
   bool updateBaseDir();
   ReturnValue_t assignAndOrCreateMostRecentFile();
 };